CA1118420A - Azetidinones and their production and use - Google Patents

Abstract

Abstract of the Disclosure Improved processes are provided for the production of a variety of azetidinones used in the partial synthesis of .beta.-lactam antibiotics. These processes begin with chlorination of various types of anhydropenicillins to produce sulfur-free dichlorides which react with water or alcohols to produce acids or esters.
These esters still contain a chlorine atom which undergoes ready intermolecular nucleophilic displacement by azide, cyanide, acetate or formate ions, or interamolecular displacement to form oxazolines, oxazolidones and oxa-anhydropenicillins. Allylic bromination of these monocyclic and bicyclic azetidinones followed by reaction with azide ion produces an allylic azide group which can be reduced to an allylic amino group. Most of the intermediates so produced are novel. From these compounds there are produced new .beta.-lactam antibiotics such as l-oxa-benzylpenicillin.

Description

11~8420 Background of the Invention (:11 Field of the Invention. - ~ne processes of the present invention produce compounds both old and new which are - u~eful -intermediates in the synthesis of ,~lactam antibiotics.

(2) Description of the prior art. - Penicillins and cephalosporins comprise a group of well-known antibacterial agents co~mnonly grouped together as a class called ~,-lactam antibiotics. For a recent review of this field with many cita-tions (especially the first ten) to the prior work see J.P.
Hou and J.W. Poole, ,B-lactam Antibiotics: Their Physico-chemical Properties and Biological Activities in Relation to Structure,'`J. Pharmaceutical Sciences, 60(4), 503-532 (April, 1971). Most of the work in this field has fundamentally been done, speaking broadly, with 6-aminopenicillanic acid, 7-amino-cephaloæporanic acid and derivatives thereof produced by fermentation.
Considerable work has also been done on total chemical ~ynthesis. A recent review is the text by M.S. Manhas and A.K. Bose, Synthesis of Penicillin, Cephalosporin C and Analogues, Marcel Decker, Inc., 95 Madison Avenue, New York, New York, 1969. An even more recent review is by R. B. Morin and B. G. Jackson, Chemistry of Cephalosporin Antibiotics, Fortschr Chem. Org. Naturst. 28, 343-403 (1970), especially pages 379-393; the now famous "Wo~sdward Intermediate" is ~hown therein as Compound 146 on page 387.

.~

Within recent months publications describing new work and su~marizing and citing older work have appeared such as:
a) from Imperial College, London, and Glaxo jointly by D. H. R. Barton et al., J. Chem. Soc. (C), 1971, 3540-3550;
b) from Oxford University by D. M. Brunwin et al., J. Chem. Soc. (C), 1971, 3756-3762;
c) from The University, Newcastle upon Tyne, by B. G. Ramsay and R. J. Stoodley, J. Chem. Soc. (C), 1971, 3859-3867;
d) from Lilly by S. Kukolja, J. Amer. Chem. Soc.
93, 6267-6270 (1971);
e) from Lilly by G. E. Gutowski et al,. Tetra-hedron Letters No. 37, 3433-3436 (1971);
f) from Lilly a series of papers entitled Chemistry of Cephalosporin Antibiotics, e.g. No. 25 in J. Medicinal Chemistry 14(11), 1136-1138 (1971) and No.
21 in J. Org. Chem., 36(9), 1259-l267 (1971).
The anhydropenicillins used as starting materials in the present invention were first described by Saul Wolfe in J. Amer. Chem. Soc. 85, 643-644 (March, 1963), Belgium 621,452 and U.S. Patent 3,311,638. Additional publications on anhydropenicillins by Saul Wolfe include Can. J. Chem.
46, 459 and 2549 (1968).
Various azetidinones having been disclosed in patents such as Sheehan's U.S. 3,487,070-072 (Class 260-239) and 3,487,090 (Class 260-326) and, for example, Woodward's .. ~.1 .

U.S. Patent 3,483,215 (Class 26~-306~7) and U.S. Patent

3,449,336 ~Class 260-243~
The oxazoline having the structure CH-CH ~ \ CH3 ~ C- N C

which is more commonly written as has been prepared from the methyl ester of benzylpenicillin in 18% yield, as by Barton et al., J. Amer. Chem. Soc., 91, 1529 (1969), and (a) above. No other bicyclic compound of this type has been described, nor has a rational synthesis of such esters or acids appeared.
~he stereochemistry of the methyl ester of benzyl-.~

penicillin (i.e. the penicillin G produced by fermentation) is represented as follows:

H H S
C6H5CH2CON ~ 1 ~ CH3 o ~ ~f~' CO CH

Kukolja [J. Amer. Chem. Soc. 93, 6267-6270 (1971 chlorinated (with 2 equivalents of chlorine) methyl 6-phthal-imidopenicillanate ~0 ~ ~ C'~2~3 to produce a mixture of the two epimers having the structure ~ - 5 -. .

4~0 Summary of the Invention This invention provides a series of processes (and certain novel intermediates produced thereby) which begin with the chlorination of an anhydropenicillin.
The processes are set forth schematically in the usual manner directly below using for illustrative purposes as the starting material the phthalimido-anhydro-penicillin having-the structure 3~N-- C--C C--O

O CH3.

For simplicity that compound is written below as H H / S ~ O
Ft ~

~ ~\/
O

TFA represents trifluoroacetic acid; DIC is diisopropyl-carbodiimide; NBS is N-bromosuccinimide; t-BuOH is tert.-butyl alcohol; Ph is phenyl.

This divisional application provides a process of producing a compound of the formula ,~
~' ~j, - 6 Div. III (C) i ~N~

- N - CH --- CH Cl ~2 // \ C//

COOH

herein Rl is hydrogen or acyl and R2is hydrogen or, in combination with Rl and the nitrogen atom to which they are attached, phthalimido which comprises saponifying a compound of the formula ~ Cl Rl _ ~ - CH-- CH

I CH~
C ~ - OR

wherein R and R have the meaning set out above and R is (lower)alkyl, trichloroethyl, benzhydryl or benzyl.

In certain embodiments the process is provided wherein R2 is hydrogen and Rl is - 6(a) -'~

Div. III (C) O R5 O o Il . l 11 11 Ar - CHC--;Ar - X - C - C -; Ar - C -;

OR
O Ar ~C- ~-C-;

,~8~cc ~; ~_C ~;

-6 (b)-:

. " ~ , .. .

420 o x ~ C - OH
Ar - NH - C -; l zl o ~ CI~

z2_ C - C -; or Rll _ NH - I - or R12 - O - C -wherein R12 represents 2,2,2-trichloroethyl or benzyl; whereln R4 represents hydrogen, amino, carbobenzoxyamino, phenyl, - fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy or (lower)alkoxy; X represents oxygen or sulfur; R5 and R6 each represent hydrogen, phenyl, benzyl, phenethyl or (lower)alkyl;
R represents (lower)alkyl; R8 and R9 each represent (lower)-alkyl, (lower)alkylthio, benzylthio, cyclohexyl, cyclopentyl, cycloheptyl, benzyl, phenethyl, phenylpropyl, furyl, thienyl, naphthyl or AR; R10 represents (lower)alkylamino, di(lower)-alkylamino, cycloalkylamino having 3 to 7 carbon atoms inclu-sive, allylamino, diallylamino, phenyl(lower)alkylamino, morpholino, lower(alkyl)morpholino, di(lower)alkylmorpholino, morpholino(lower)alkylamino, pyrrolidino, (lower)alkylpyrroli-dino, di(lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino, di(lower)alkylpiperidino, 1,2,5,6-tetrahydropyridino, N-(lower)alkylpiperazino, N-phenyl-piperazino, N-(lower)alkyl(lower)alkylpiperazino, N-(lower) alkyl-di-(lower)alkylpiperazino, furfurylamino, tetrahydro-furfurylamino, N-(lower)alkyl-N-furfurylamino, N-alkyl-N-anilino or (lower)alkoxyanilino; zl, z2 and Z3 each represent (lower)alkyl or Ar-; Rll represents (lower)alkyl, (lower)-cycloalkyl~ naphthyl, benzyl, phenethyl or ~ i - 6c -~., 4~0 Ar - C -and Ar represents a monovalent radical having the formula Rl Rl R

R2 ~ 1 ~

wherein Rl, R2 and R3 are each hydrogen, chloro, bromo, iodo, trifluorome~hyl, phenyl, (lower)alkyl or (lower)alkoxy, but only one of said Rl, R2 and R3 groups may represent phenyl.

-6'd)-' ~, J . 1~1~3420 ~0 C1 _ _ ,~ N ~ ~ N~

7 COCl C~Cl 3a ~a 4b 9 (~ee KukolJa, ~upra) 10 ' * * *
11 H C1 H Cl 12 Ft~ t-BuOHFt ~
1~ //~N~ ~N~J
14 A C~
COCl 02t-Bu 16 4a 4g 1~ I CH OH ¦ qFA
18 ~ 3 19 H Cl H Cl Ft~ - CH2N2 Ft_~
21 0 /)~ O ~ /

23 C02CH3 ~ COOH

24 ;~ NaN3 \
26 H N3 \ H Cl 27 Ft~ \ 2NBS ~ Ft~
2 o//L \_J 0~ \~

4h 8a 420 '~ ~

, 2 H Cl 3 Ft~
4 0~/ \_ /

/--\ 4e 6 . . C02CH~
7 H Cl \ 1 NBS ~ Ci 10 --/ 0~\~
11 /--\_ Br H Cl H Cl Ft~ + Ft~

16 0 V ~ N~--_N3 8 8e ~ 3 ~ ~_ Ft~ + Ft~
22 o// \ J ~L N ~ NH2 23 8 C~ NH2 C02C~3 8h 24 ~ ~¦~KO-tBu ~ _ _ H H H
26 Ft~\
0// N~ CH~5 28 C02Me 9 * * *

Il ~ 9-C-H
Ft ~ H
2 ~ NJ,~
3 . 0 4 ~02C~3 1` ~ 4 6 1 ~-C-X

9 Ft~ Ft~rl ~L N~ CH3 > 0 V

12 ~b d~\ / / C2C~3 ~,~ NaN3 H 0-AC / ~ ~

7 ~\ J ! Ft ~J
19 C~\ ''C2C~3 ~NBS 4 4~ _~

22 H C1 - H C=1 23 ~,t,;;~ + t 26 CO2CH~5 Br CO2C~

29 * * *

-3420 ?

1 The above and additional processes and intermedlates of the 2 pre~ent lnventlon are set ~orth below uslng as the 3tart~ng mater~al 3 the toluenesulfonlc acid (TsOH) salt of 6-aminoanhydropeniclllin, 4 This compound has the structure.

5 H =H/ S \
TsOH-H2N _ IC C C = 0 . 0~ C~ / CX3 8 . CX~ which ~or convenlence i3 represented below a~

12 H H S ~ o 13 Ts ~ ~ '' 14 /~

18 * *

~2 3420 --"~
., , 2 ~S~O Te~ = ~

0 ~ ~ ~ \J
Cl v ~.b, 8 H Cl H Cl 9 ~ Ts ~ ~ Ts 11 ~ ' o V o~
12 COOH . COOH
13- ~ ~ CH~;OH 5c sd 14 H Cl H Cl ~I!a~ 1. NaHCO~ . Pt~

l6 0// \ J 2. ~-C02Et ~
18 5e C2CH 5 ,C,~ 4 C2CH3 _- .
19 (one isomer i~olated) 21 H Cl ~¦,HCO ~;- H C
22 H2N ~ ~ H2N r-23 ,~ N~_ C02CH3 . C2CH3 26 _~ 6b 28 * ~ *

3o ? 1~1~42V

l H Cl H Cl 4 ~ T~ 5d 5c COOH COOH

6 1 1 ,¦, NallC03 8 ,1,, 10~ ~- ~

14 . C2H I C2H
PhCH2COCl / \ ~ PhCH2COC l 18 H H H Cl ~9 ~CH2CONH~ PhCH2CONH~
~ ~NJ~

22 ,COOH COOH
2' 3o - ~ * *

2 X Cl 3 H2N ~
/ X a 6 j ___ . C02CE~

7 i ~(CH2COOH N 5

8~ DIC /
~I Cl HN=~5 10~I2CONH ~ .H2N ~
N // NX

13 7a ~ C02CH S 6d 1115 ~7c~¦Slllca \ ~I~DIC

17 7 /0 _ 3 18 H ~ " H ~CH2CONH

~ X // N~
21 ~o2CH3 - C2CH3 22 2 7d ~7 ZO

2 ~ Cl 3 ~ H2N~
4 ,~ N~ ~/
O

6 , 1 I 6b 8 ~ DIC --~N~;0

9 ~I Cl ~I ~

10~CH2CONH r¦ X2N~ 6c 12~ ~ 0~

141 spontaneOu~
15cyc lizat ion ~CX2COOH
16 ~ \ DIC
~7 0 , ~I ~3 O / \~J ~IzCONH ~ 7c 21 CO/~ i NaHC03 GO
22 I,2NBS

23 H ,~,COCH2~ H N
24 ~H2CONH ~ ~ ~CH2CoNH~3 225 /~N~J /~N ~ ~r 27 7e C2CH3 C2 3 8i * * *

` ~ ~

H Cl 3 Ft ~

4 0~ \ /
/~
6 I C~2CH3 4e ~) (3 7 Et~ NCl 8 H Cl H Cl g Ft ~ t rl 10o/)~ N~J

11 C~ . C2CH3

12

13 I~e 2 parts ~-5 parts ~'

14 . . Et4NCl 17 ~ Ql 18 Ft 19 ,~ N~J

21 C02CH~

23 * * *

24 H Cl H Cl H Cl H2N~ C ~ 6--\

28 6a C02CH ~ 6~ C2CH3 C 2CH~ 6b 29 ~ 1 part 6 parts

- 15 -11~8420 Thus, direct chlorination (excess C12, CR2C12, 20, 3 min.~ of anhydro-6-p~thal~midopenicillin (3a), followed by removal of the solvent under reduced pressure, afforded a 3:2 mixture of two isomeric compounds. The major isomer 4a, m.p.
210 dec., was obtained in 38% yield (from 3a) by crystalliza-tion from CHC13-petroleum ether (calcd. for C16H12N2O4Cl: C, 52.3: H, 3.31; N, 7.69; Cl, 19.4. Found: C, 52.03; H, 2.96;
N, 7.76; Cl, 19.53), ~EmaxH 242 (10000). The ir spectrum of ~ (and of the mixture of a and 4b) shows peaks at 5.48 (COCl), 5.55 ~-lactam), 5.62, 5.79 ~(phthalimido).
Hydrolysis of 4a (boric acid-borax buffer ~Saul Wolfe, R.N. Bassett S.M. Caldwell, and F.I. Wasson, J. Amer. Chem.
Soc., 91, 7205 (1969~ or aqueous acetone) gave the acid 4c, m.p. 168-174 dec. in 73% yield (calcd. for C16H13N2O5Cl:
C, 55.05; H, 3,76; N, 8.02; Cl, 10.02; Found: C,54.65; H, 3.79; N, 8.46; Cl, 10.53); ~EmtaxH 236 (7400), 296 (1800);
~XBr 5.52, 5.60, 5.80, 5.85 ~. Methylation of 4c (CH2N2, Et2O-CH2C12) produced the ester 4e, m.p. 178-180 dec. in 97% yield. The same compound was obtained from 4a in 93%
yield upon treatment with absolute methanol (30 min., 20).
Treatment of the mixture of 4_ and 4b with methanol (30 min., 20) and crystallization of the resultant residue (CHC13-petroleum ether) afforded 4e in 55~ yield. Chromatography of the residual mother liquor (Woelm II alumina; 1:1 CH2C12:C6H6) produced 22% of 4f, the methyl ester derivative of 4b, m.p.
192-194, in the first fractions followed by an additional 9% of 4 . The t-butyl ester 4g was obtained in 33~ yield by refluxing 4a in anhydrous t-BuOH for 21 hr. Dissolution of 4~ in trifluoroacetic acid and evaporation of the solvent after 3 min. gave a in quantitative yield.
The relative amounts of 4~ and 4b were not signific-antly affected by chlorination in the presence of excess ~ i - 16 -i~

8~0 Et4~Cl, other c~loxinating agents ~SO2C12~ p~vxidinium trichlor-ide, pyrrolidone h~drotrichIoridel gave more complex mixtures.
The esters ~e and 4f were equilibrated [Under identical experi-mental conditions the same mixture was obtained from both direc-tion~ upon refluxing (Me2CO, 12 hr~; 2-butanone, 4 hr.) with excess Et4~Cl , the trans isomer 4f predominating. Depending on the conditions, ratios varying from 3:2 to 5:2 could be obtained and the isomers could be separated by chromatography, as des-c~bed above.
Reaction of 4e with sodium azide [4c decomposed when subjected to these condition~ (DMF, 90, 3 hr.) afforded the trans azide 4h, m.p. 144-145 (67%); under the same conditions 4f was converted to 4i, m.p. 183-187 (52%). Reaction of 4f with Et4~0Ac (pure CHC13, reflux, 17 hr.) gave the cis-acetate 4~ (62~). Reaction of 4f with tetramethylguanidinium formate [a reagent invented for this purpos~ afforded the cis-formate 4k (35~).
The above sequence of reactions was then repeated, with various modifications, on the p-toluenesulfonic acid salt [S.
Wolfe, Can. J. Chem., 46, 459 (1968~ of anhydro-6-aminopenicil-lin.
(3b). Chlorination (0-5, CH2C12), followed by removal o the solvent and trituration with ether, afforded by a 4:1 mixture of 5a and Sb as a stable (below 20) white powder, m.p.
148-149 dec. Hydrolysis of this powder (acetone-water) gave a 4:1 mixture of the acids 5c and 5d. Alternatively, methanol _, treatment of the mixture of Sa and 5b, and crystallization from chloroform-hexane produced the pure cis-chloromethyl ester 5e, m.p. 125-130 dec., in 67% yield. Neutralization of 5e (NaHCO3) and reaction of the free base 6a with N-carbethoxyphthalimide LG.H.L. Nefkens, Nature, 185, 309 (1960~ gave 4_ to provide confirmation that the chlorination reaction had proceeded in the ' .~, ,, same manner with the tW~ anhydropenicillins~
Equilibration of 6a ~ith thè trans isomer 6b proceeded smoothly ~n the presence of chloride ions, the optimum ratio in favor of 6b ~6:1) being achieved with tetramethylguanidinium chloride tCH2C12, 12 hr. reflux~. The isomers were separated by alumina chromatography. The cis amino chloride 6a reacted smoothly with tetramethylguanidinium azide ~A.J. Papa, J. Org.
Chem., 31, 1426 (1966~ (2 equiv., CHC13, 1 hr. reflux) to give the trans amino azide 6d (90%); the cls amino azide 6c, m.p.
116-117, was obtained similarly from 6r~b in 85% yield.
The 5-chloropenicillin G analog 7a, m.p. 111-115 dec., was obtained (82~) upon phenylacetylation of 6a (PhCH2COOH, diisopropylcarbodiimide (DIC), CH2C12). The C5 epimer 7b, ob-taine~ similarly from 6b, cyclized spontaneously to the oxazo-line 2 ~J.C. Sheehan, "Molecular Modification in Drug Design", Advances in Chemistry Series, No. 45, American Chemical Society, Washington, D.C., 1964, page 15.; D.H.R. Barton, F. Comer and P.G. Sammes, J. Amer. Chem. Soc., 91, 1529 (1969)] , m.p. 126.5-127; additional quantities of ~ were obtained from 7a by rapid chromatography on silica gel or alumina ~If the trans-acylamino chloride ~ was shaken with bicarbonate varying guantities (up to 10%) of 7e could be isolated in addition to the oxazoline~ . The 5-azidopenicillin G analog 7c, m.p. 102-103 , was obtained (83~) upon phenylacetylation of 6c (PhCH2COOH, DIC, CH2C12); the C5 epimer 7d was obtained similarly from 6d or by reaction of 7a with tetramethylguanidinium azide (CHC13, reflux).
Allylic oxidation of ~ by N-bromosuccinimide (NBS, 2 equiv., CC14, benzoyl peroxide, Photoflood No. 2 bulb ~S. Wolfe, and D~V.C. Awang, Can. J. Chem., 49, 1384 ~1971~; This result should be contrasted to the behaviour o~ the parent anhydro-penicillin towards allylic oxidation; S~ ~olfe, C. Ferrari and W.S. Lee, Tetrahedron Letters, 3385 (196~ As already noted, S. Wolfe, R.N. Bassett, S.M. Caldwell, and F. I. Wasson, J.
Amer. Chem. Soc., 91, 7205 (1969), enamine character of the-double bond of these compounds is not seen in the monocyclic systems~) was complete within 5 min. The product 8a crystalliz-ed from CC14-petroleum ether in 81% yield, m.p. 70-72 dec.
Under the same conditions the C5 epimer 4f afforded 8b (70%).
The extraordinary facility of this NBS oxidation is seen in the successful functionalization, under the same conditions, of 7c and 2. The methyl groups of 4e and 4f show no signifi-cant difference in reactivity. Thus, oxidation of 4e with one equivalent of NBS afforded a 1:1 mixture of 8c and 8d. Treat-ment of this mixture with tetramethylguanidinium azide (one equivalent, CHC13, 3 hr., 20 ~The 5-chlorosubstituent is stable under these conditions.~ ) afforded a 1:1 mixture of 8e and 8f; ~ mHaCxl3 4.7 (azide), 5.55 (R-lactam), 5.62, 5.79 (phthalimido), 5.78 (ester). Hydrogenation (PtO2, benzene, 45 psi, 6 hr.) yield the mixture of amines 8~ and 8hi ~~mHaCxl3 5.55, 5.62, 5.79, 5.83 ~ . This mixture was recovered unchanged following refluxing in chloroform. Treatment with KOtBu-tBuOH
~20, 1 hr.), followed by careful chromatography (neutral alumina, activity II, elution with graded mixtures of C6H6-CH2C12) produced in 12% yield (24% if only one of 8g or ~h reacted) a crystalline compound, m.p. 121-122 having structure 9 on the basis of its ir (7~mBarx 2.92, 5.56, 5.62, 5.79, 5.82 6.03~ ) and nmr (2.25 (4H), 3.87 (l~H,d,2.0 Hz), 4.30 (lH,d,2.0 Hz), 6.23 (3H), 7.70 (2H), 7.88 (3H)) spectra.

2~

1 Another important embodiment o~ the present lnvention i8 2 schematlcally lllustrated, with R indicating n-propyl or tert.
3 butyl and 4 ll ~
HMPT indicating (CH3)2N-I-N(CH~)2 6 N(CH~)2 as follows: CH2Ph N ~ O

~ H
12 ~/ N

1. RSLitHMPT

16 ~ f 2. H30 U Cl H2Ph 9 + PhCH CONH ~ ~ 'CH3 Hl~ H 2 L I ~ / 0// ~ "'COOH
21 o" ~
22 COOH (as in U.S. ( 3)3 2, patent ) / 3 CH~OH

26 .H H ~CH3 27 H2N ~ ~ 'ICH~
28 0~ ~ ~COOH

* * *

~/ ~ 2 X oi Ft~C~3 4 ,~ N ~ / N ~""'COOH

6 4. ~I~jO~
7 ~ H2N-NH2 or CH3NH2 8 . (a3. in S. Wolfe and S,K.
Hasan, Can. J. Chem., g 48, 3572 (1970)). .

11 - H N ~ yCH

13 . X

16 *

17

18

19 21~

!

2 H Cl 3 Ftl~

/ \ 4r 6 . C02CH~5 _ 7 H Cl 1 NBS H Cl 8 ~ = \ + Ft~:
9 //~N / - ~N~ Br /~\_ Br /--\ -H Cl H Cl 16 eO/r~\J ~
17 ~ N~ C2CH3 8 ~

H Cl H Cl Ft~ + Ft~

22 0 / ~ N ~NH2 2~ C~ NH2 ~ co2 24 ~ KO-tBu _ H H H
26 F ~1 -r 27 ~l N~ CH3 * * *

~ .

420 -~

l More generally speaking, the processes described above and 2 ln the examples are conducted with numerou~ slde-chain~ at the 6-po~itlon, e.g.- uslng as the origlnal reagent an anhydropenlcillln 4 havlng the rormula ~ -~S\
6 R - CH C~ C _ O
7 //C _ N C = C(CH~)2 9 wherein Rl represent~ acylamino, includlng phthallmldo, or 10 amlnO-ll m us in the processes hereln disclosed use i~ also made 12 ln pla¢e o~ the phthallmido group (Ft) or the free amino group 13 or lt~ to~ylate (T~) o~ the corre~pondlng reagents, lntermedlate~
14 and produ¢ts ~n whlch-each of these groups i8 replaced by an a¢ylamlno group Rl o~ the ~ormula U
~ 0 R5 1l 14 ; Ar - X - C - C - NH-21 : oR7 223 Ar- C ~ NH-- ;
24 ~
- ~>
26 Ar 8 ~C - NE-- , R8~L~ ~ NE-- ;

, -2~-42~
o C ~ Rl Q X

C - ~ - ; Ar - N~ - ~ - N~ -C - OH Z
- NH - z2 1 - C - NH - and X ' o Rll - NH - C - NH - , and R12 - O - C - ~H -wherein R4 represents a member selected from the group consist-ing of hydrogen, amino, carbobenzoxyamino, phenyl, fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy and (lower)-alkoxy; X represents a member selected from the group consist-ing of oxygen and sulfur; R5 and R6 each represent a member selected from the group consisting of hydrogen, phenyl, benzyl, phenethyl and (lower)alkyl; R7 represents (lower)alkyl; R8 and R9 each represent a member selected from the group con-s~ting of (lower)alkyl, (lower)alkylthio, benzylthio, cyclo-hexyl, cyclopentyl, cycloheptyl, benzyl, phenethyl, phenyl-propyl, furyl, thienyl, naphthyl and Ar- R10 represents a member selected from the group consisting of (lower)alkyl-amino, di(lower)alkylamino, cycloalkylamino having from 3 to 7 carbon atoms inclusive, allylamino, diallylamino, phenyl-(lower)alkylamino, morpholino, lower(alkyl)morpholino, di-(lower)alkylmorpholino, morpholino(lower)alkylamino, pyrroli-dino, (lower)alkylpyrrolidino, di(lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino, di-~ ~B~V
(lower~alkylpiperidino, 1,2,5,6-tetrahydropyridino, N-(lower)-alkylpiperazino, N-phenylpiperazino, N-Clower)alkyl(lower)-alkylpiperazino, N-(lower)alkyl-di-Clower)alkylpiperazinG, furfurylamino, tetrahydrofurfurylamino, N-(lower)alkyl-N-furfurylamino, N-alkyl-N-anilino and (lower)alkoxyanilino;
zl, z2 and Z3 each.represent a member selected from the group consisting of (lower)alkyl and Ar-; Rll represents a member selected from the group consisting of (lower)alkyl, (lower)-cycloalkyl, naphthyl, benzyl, phenethyl and Ar C~O; R12 represents 2,2,2-trichloroethyl or benzyl and Ar- represents a monovalent radical having one of the formula ;

R2 ~

wherein Rl, R2 and R3 are each a member selected from the group consisting of hydrogen, chloro, bromo, iodo, trifluoro-

20 methyl, phenyl, (lower)alkyl and (lower)alkoxy, but only one of said R , R and R3 may represent phenyl.
Thus, for example, a preferred group of intermediates and final products of the present invention are illustrated in terms of final products by acids having the following formulae:

o - CH - C - NH - Cd CH / C(CH3)2 R O C N CHCOOH

30 wherein R represents (lower)aikyl;

R2 3L~ 420 ~ C - NH - CH - CH C(CH3)~
R3 ~ Rl = C W CH-COOH

wherein Rl represents (lower)alkyl and R2 and R3 each repre-sent a member selected from the group consisting of hydrogen and chloro;

Rl C - NH - CH ¦ f ~ R2 N CH-COOH

wherein Rl is (lower)alkyl and R2 is a member selected from the group consisting of hydrogen and chloro;

C - NHR

C - NH - fH IH ~ \ C(CH3)2 O C N CH-COOH
wherein R represents (lower)alkyl;

CH - 1 - NH - CH CH \ C(CH3)2 ~ o - C - R o C N CH-COOH

wherein R is (lower)alkyl;

~ - 26 -4zo OR

~C - NH - CH --CH f ( CH 3 ) 2 ~ ' ~

wherein R is (lower)alkyl;

o - CH - C - NH - fH CH fH2 O= C N .~C - CH3 COOH

wherein R represents (lower) alkyl ;

N~ _ f~_ fH \c~2 Rl O=C N \ D C - CH 3 COOH

wherein Rl represents (lower)alkyl and R2 and R3 each re-present a member selected from the group consisting of hydrogen and chloro;
O N
Rl N I C- NH - fH TH lcH2 ' ~,S \ c D
COOH
wherein Rl is (lower)alkyl and R2 is a member selected from the group consisting of hydrogen and chloro;

,.

ZO

0 , ~c O--C - N ~C -- CH3 COOH
wherein R represents (lower)alkyl; H

CH - c - NH -CH = \ c COOH

wherein R is (lower)alkyl;
OR H

C - NH - CH CH / \

O-- C N \ ~C - CH3 COOH

wherein R i8 (lower)alkyl.
The present invention provides the process for the production of an antibacterial agent which comprises reacting a compound of the formula /0\
H N - fH TH l(CH3)2 C N CH - COOH
o or a salt thereof with an organic monocarboxylic acid chloride s, - 28 -or a functional equivalent thereof, and also the process for the production of an antibacterial agent which comprises reactiong a compound of the formula H
H2N - CH lH f~2 O C _ C - CH3 COOH

or a salt thereof with an organic monocarboxylic acid chloride or a functional equivalent thereof.
In a preferred embodiment the present invention pro-vides the process for the production of an antibacterial agent wh~ch comprises reacting a compound of the formula O H
H2N ~ H CH / \ C(CH3)2 / N

f I I or H2N - CH CH CH2 C N CH-COOH
O -C N \ ~ C-CH3 OOH

or a salt thereof either with an organic monocarboxylic acid chloride of the formula Ar - CH~ - Cl ; Ar - X - C - C - C1 Ar - C - Cl ; OR

~ - C - Cl : - 29 -C - Cl ~ ~ JL R9 Il _ Rl , :~

C - Cl ; Ar - N~ - C - Cl O

C Cl ; z2 _ C - C - Cl and O Z :
X
Rll _ NH - C - Cl wherein Rl represents a member selected from the group con-sisting of hydrogen, amino, carbobenzoxyamino, phenyl, fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy and (lower)-alkoxy; X represents a member selected from the group con-sisting of oxygen and sulfur; R5 and R6 each represent a mem-ber selected from the group consisting of hydrogen, phenyl, benzyl, phenethyl and (lower)alkyl; R7 represents (lower)-alkyl; R and R9 each represent a member selected from the group consisting of (lower)alkyl, (lower)alkylthio, benzyl-thio, cyclohexyl, cyclopentyl, cycloheptyl, benzyl, phenethyl, phenylpropyl, furyl, thienyl, naphthyl and Ar-; R10 represents a member selected from the group consisting of (lower)alkyl-amino, di(lower)alkylamino, cycloalkylamino having from 3 to 7 carbon atoms inclusive, allylamino, diallylamino, phenyl-(lower)alkylamino, morpholino, (lower)alkylmorpholino, di-(lower)alkylmorpholino, morpholino(lower)alkylamino, pyrroli-~18420 dino, (lower)alkylpyrrolidino, di(lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino, di(lower)alkylpiperidino, 1,2,5,6-tetrahydropyridino, N-(lower)alkylpiperazino, N-phenylpiperazino, N-(lower)alkyl-~lower)alkylpiperazino, N-(lower)alkyl-di-(lower)alkylpiper-azino, furfurylamino, tetrahydrofurfurylamino, N-(lower)-~
alkyl-N-furfurylamino, N-alkyl-N-anilino and (lower)alkoxy-anilino; zl, z2 and Z3 each represent a member selected from the group consisting of (lower)alkyl and Ar-; Rll represents a member selected from the group consisting of (lower)alkyl, (lower)cycloalkyl, naphthyl, benzyl, phenethyl and Ar-C -, and Ar- represents a monovalent radical having one of the formulae 1 R Rl R ~ , ~ and R2 ~

wherein Rl, R2 and R3 are each a member selected from the group consisting of hydrogen, chloro, bromo, iodo, trifluoro-methyl, phenyl, (lower)alkyl and (lower)alkoxy, but only one ~ group may repre ent phenyl; or with a functional equivalent of said acid chloride.
The term "(lower)alkyl" as used herein means both straight and branched chain aliphatic hydrocarbon radicals having from one to ten carbon atoms such as methyl, ethyl, propyl, isopropol, butyl, isobutyl, t-butyl, amyl, hexyl, 2-ethylhexyl, heptyl, decyl, etc. Similarly, where the term "(lower)" is used as part of the description of another group, e.g. "~lower)alkoxy", it refers to the alkyl portion of such group which is therefore as described above in connection with "(lower)alkyl".

The functional e~uiYalents o the above acid chlorides as an acylating agent for a pri~nary amino group include the corresponding carboxylic acid bromides, acid anhydrides, in-cluding mixed anhydrides and particularly the mixed anhydrides prepared from stronger acids such as the lower aliphatic mono-esters of carbonic acid of alkyl and aryl sulfonic acids and of more hindered acids such as diphenylacetic acid. In addi-tion, an acid azide or an active ester or thioester (e.g.
with p-nitrophenol, 2,~-dinitrophenol, thiophenol, thioacetic acid) may be used or the free acid itself may be coupled with the primary amine after first reacting said free acid with N,N'-dimethylchloroformiminium chloride ~cf. Great l~ritain 1,008,170 and Novak and Weichet, Experientia XXI/6, 360 (1965)~ or by the use of enzymes or of an N,N'-carbonyl-diimidazole or an N,N'-carbonylditriazole ~cf. South African Patent Specification 63/2684~, of a carbodiimide reagent tespecially N,N'-dicyclohexylcarbodiimide, N,N'-diisopropyl-carbodiimide or N-cyclohexyl-N'-(2-morpholinoethyl)carbodi-imide; cf. Sheehan and Hess, J. Amer. Chem. Soc. 77, 1067, ~1955)1, or of alkynylamine reagent Ccf. R. Buijle and H. G.
Viehe, Angew. Chem. International Edition 3, 582 (1964)], or o a ketenimine reagent ~cf. C. L. Stevens and M. E. Monk, J. Amer. Chem. Soc. 80, 4065 (1958)] or of an isoxazolium salt reagent ~cf. R. B. Woodward, R. A. Olofson and H. Mayer, J. Amer. Chem. Soc. 83, 1010 (1961)~. Another equivalent of the acid chloride is a corresponding azolide, i.e. an amide of the corresponding acid whose amide nitrogen is a member of a guasi-aromatic five-membered ring containing at least two nitrogen atoms, i.e. imidazole, pyrazole, the triazoles, benzimidazole, benzotriazole and their substituted derivatives.
As an example of the general method for the preparation of an azolide, N,N'-carbonyl diimidazole is reacted with a carboxy -,~

lic acid in equimolar prop~rtions at room temperature in tetrah~drofuran, chloroform, dimethylformamide or a similar inert solvent to form the carboxylic acid imidazolide in practically quantitati~e yield with liberation of carbon dioxide and one mole of imidazole. Dicarboxylic acids yield diimidazolides. The by-product, imidazole, precipitates and may be separated and the imidazolide isolated but this is not essential. The methods for carrying out these reactions to p~oduce a penicillin and the methods used to isolate the penicillins so-produced are well-known in the art.
The nontoxic, pharmaceutically acceptable salts include metallic salts such as sodium, potassium, calcium and aluminum, the ammonium salt and substituted ammonium salts, e.g. salts of such nontoxic amines as trialkylamines, including triethylamine, procaine, dibenzylamine, N-benzyl-beta-phenethylamine, l-ephenamine, N,N'-dibenzylethylenedi-amine, dehydroabietylamine, N,N'-bis-dehydroabietylethylene-diamine, N-(lower)alkylpiperidines, e.g. N-ethylpiperidine, and other amines which have been used to form salts with benzylpenicillin.
There are particularly included within the scope of the present invention the antibacterial agents which are prepared in the above-described acylation process by the use therein of the or~anic monocarboxylic acids or their acid chlorides or other equivalents which have previously been used to acylate 6-aminopenicillanic acid as described, for example, in U.S. Patents 2,941,995; 2,951,839; 2,985,648;
2,996,501; 3,007,920; 3,025,290; 3,028,379; 3,035,047;
3,040,032; 3,040,033; 3,041,332; 3,041,333; 3,043,831;
3~053,831; 3,071,575; 3,071,576; 3,079,305; 3,079,306;
3,080,356; 3,082,204; 3,093,547; 3,093,633; 3,116,285;
3,117,119; 3,118,877; 3,120,512; 3,120,513; 3,120,514;

~!

3,127,394, 3,1~0,282, 3,142,673; 3,147,247; 3,174,964: , 3,180,863; 3,198,8~)4; 3,202,653; 3,2Q2,654; 3,202,6~5;
3,210,337; 3,157,639; 3,134,767; 3,132fl36; in British Patent Specifications 874,414; 874,416, 876,516; 876,662: 877,120;
- 877,323; 877,531, 878,233; 880,042; 880,400; 882,335; 888,110;
888,552; 889,066; 889,069; 889,070; 889,168; 889,231, 890,-201;
891,174; 891,279; 891,586; 891,777; 891,938; 893,518; 894,247;
894,45~; 894,460; 896,072; 899,199; 900,666; 902,703; 903,785;
904,576: 905,778: 906,383: 908,787; 914,419; 916,097; 916,204;
916,205; 916,488; 918,169; 920,176; 920,177; 920,300; 921,513;
922,278 924,037; 925,281; 931,567: 932,644; 938,066, 938,321, 939,708; 940,488; 943,608; 944,417; in numerous Belgian Patents! e.g. 593,222; 595,171; 597,859; 602,494; 603,703;
609,039; 616,419; 617,187; and in South African Patent Appli-cations, e.g. 60/2882; 60/3057; 60/3748; 61/1649; R61/2751;
62/54; 62/4920; 63/1612 and 63/2423.
When the acylamino group of the compounds of the pre ent invention also contains a strongly basic group, e.g.
primary amino, as in the case of the preferred embodiments having the formulae 1l / \
Ar - CH - C - NH - CH- fH f (CH3) 2 NH2 --C N CHCOOH and H

Ar - CH - C - NH - CH N

O C N \ C -- CH 3 COOH

wherein Ar is as defined above (and Rl, R2 and R3 in Ar are preferably hydrogen), the products are emphoteric and normally exist in the zwiterrion form but can form acid addition salts, ~ - 34 -, as with such nontoxic, pharmaceutically acceptable organic ac~ds as acetic, citric, succin;c, ascorbic and the like and with inorganic acids such as hydrochloric, hydrobromic, sul-furic, phosphoric and the like.
The processes of the present invention also include the use as "final reage~ts" of the compound of the formula / o \
H2N - CH - CH C(CH3)2 O - C N CHCOOH

and its salts with acids and bases and the compound of the formula H
/ N \

C N \ ~ C - CH3 O C

COOH

and its salts with acids and bases.

These "final reagents" are prepared, for example, by subjecting to hydrogenolysis the compound of the formula O O

C6H5CH2O - C - NH - fH fH f (CH3)2 C ~ N CH
o o=f or by subjecting to hydrogenolysis the compound of the formula ll N \
C H CH2O - C - NH - fH CH fH2 C N \ ~ C - CH3 o f ,o, ~- 3S -1~L8420 or by sub~ecting to acid cleavage either the compound of the 2 fOr~l~ulaH

4 (CH3)3 -C - O - C - NH - CH--CH CH2 11 \c~ CH~
7 O=C - O - C(CH3)3 or 8 the compound of the f or.mula ./ \
(C6H5)~C - NH - CH--CH ICX2 11 C ~ N C - CH
12 . o C
13 , . O--C - o - C(C6H5)3 16 . . . .
7 or by treating with zinc and acet~c acid the compound of the 18 fOrmula o / \

21 Cl~C-CX~0-C-NX - CH - CH f (CH3)3

22 . ~ C N CH

23 0 = C

24 0CX2CC13 26 or the compound of the f ormula 27 0 /N\
2~ Cl3c-cH2o-c-NH - CIH ~ IH CIH2 O_C - OCH2CC1 ., .

4~

Such esters are prepared, for example, by using as the starting material an anhydropenicillin of the formula / \
R - CH CH C = 0 ~C N C = C(CH3)2 o in which Rl is C6H5CH2O-C-NH- , (CH3)3C-O-C-NH-~ ~- Cl-C-C~20-C-N~{-formyl, o-nitrophenylsulfenylamino or o-nitrophenoxyacet-amido or one of its equivalents as described in U.S. patent 3,271,409; and in the appropriate later step (of reaction with acid chloride) substituting for the methanol either t-butyl alcohol or trityl alcohol or trichloroethyl alcohol;
or in the later step (of reaction with carboxylic acid) substituting for the diazomethane either diphenyldiazomethane, 2,2,2-trichloroethyl chloroformate, benzyl chloroformate, or t-butyl chloroformate.
These esters are then converted to "final reagents"
by removal of the ester and conversion of the blocked amino group to a free amino group, either consecutively or simultaneously. Thus, when the blocked amino group repre-sents phthalimido, it is converted to primary amino by treat-ment with hydrazine hydrate in dioxane at about room tempera-ture for at least twelve hours or with methylamine in aqueous dioxane. When the blocked amino group ,~ ~ - 37 -~ 3420 1 represent~ carbobenz~loxyamino it ls converted to a prlmary 2 amino group by catalytlc hydrogenation to leave the product.
3 When the blocked amino group is ~ormyl, carbo-t-butylo~y-amlno 4 or o-nltrophenylsulfenylamlno it ls converted to prlmary amlno elther by reaction wlth anhydrous hydrogen chloride ln a non-6 protonating solvent such a~ benzene or methylene chloride or by 7 reaction with trifluoroacetic acld. The trlchloroethoxycarbonyl-8 amino 18 converted to primary amlno by reactlon with zinc in 9 aqueous acetic acld. In additionj when the blocked amlno group ~ carbo-t-butyloxyamino, the ~inal two reactions are 11 conducted in one step by the use of stronger aoid for longer 12 perlods o~ tlme and, 1~ desired, at hlgher temperatures.
13 When the blocked amino group is o-nitrophenoxyacetamido, it 14 ls converted lnto a primary amino group by either (a) catalytlc hydrogenation (e.g. In water at room temperature using 30~ Pd-on-16 dlatomaceous earth) followed by allowing the m~xture to stand at an 17 ac~dlc pH (e.g. in water acidified to pH 2 wlth 20% hydrochloric 18 acid at about 10 C. for at least 20 minutes or at 25 C. for at 19 least 24 hours) or (b) b~ addlng the blocked compound (e.g. 7 milllmoles) ln cold water, e.g. 30 ml., rapldly, e.g. over 21 1-~ mlnutes, to 5~ Pd-C (e.g. 0.05 g.) suspended in a cold solution of B H4, (e.g. 14 millimole~) d~ssolved in water, e.g.
2~ 70 ml.

Chlorination of Anhvdro-6-Phthalimido~en~cillin 2 Chlorine gas was passed at room temperature lnto a 3 solution o~ anhydro-6-phthallmidopenlcillln (500 mg., 1.52 4 mmoles) ln methylene chlor$de (15 ml.). The gas lntroduction was terminated after 3 minutes and,after an addltional 5 6 mlnultes, the yellow solutlon was evaporated to dryneas. The 7 resulting whlte ~oam wa~ crystallized from a mi~ture o~
8 chloro~orm and petroleum ether to give a total of 250 mg.
9 (32%) Or materlal in two crops, m.p. 210 dec. The IR
10 spectrum of the re31dual mother liquor waa ldentl~al to that 11 o~ the crystalline material, aun~arlzed below.
12 Anal. Calcd. for C16H12N204C12: , 5 1~ Cl, 19,4.
14 Found: C, 52.03; H, 2.96; N, 7.76; Cl, 19.53.
~e IR spectrum~shows peaks ln the carbonyl reglon at 16 5.48, 5.55, 5.62 and 5.79~,. The ~ spectrum show3 peaks 17 at 2.13 (4H), 3.78(1H,d,J=4.2 Hz), 4.24 (lH,d,J=4.2 Hz), 18 7,60 (3H), 7,69 (3H), The uv spectrum showa~EmtxH 242 (10,000).
9 ~!he compound has the atructure ~

22 COCl 3~
~39~
.

.. , ., ., __ . _, . . _ . -- _ . . .--, . , . r--420 `-~

l H~drol~is o~ the Dichloride 2 m e dichlorlde (500 mg., 1.36 mmole~)~ in dimethyl sul~oxide, 3 (500 ml.) was treated, dropwiæe at 0, with 50 ml. of a pH 7.95 4 buffer (prepared by dlluting 50 ml. Or O.lM boric acid and 2.6 ml. of O.lM NaOH to lOO ml.). At the end of the addition, the 6 pH of the reaction mixture wa~ 6.8. This mixture was allowed 7 to warm to room temperature, and stirring wa~ cantinued for 8 ~.25 hours. Then ice-cold water (300 ml.) wa~ added, the 4 mixture brought to pH 3 with ice-coldN HCl, and extracted with rive lOO ml. portlon~ of methylene chloride. The combined extracts ll were washed twice wlth water (100 ml. portions) and drled over 12 anhydrous sodium sulfate. Evaporation under reduced pressure 13 at 40 afforded a mobile liquid which contalned a considerable 14 amount of DM$0. This was redissolved in chloroform t60 ml.) and the ~olution washed ten tlmes with water (10 ml. portions).
16 After drying and evaporatlon there was obtained from the chloro~orm 17 phase 0.59 g. o~ a cry~talline white solid. This was recrystallized 18 ~rom a mixture o~ chloroform and petroleum ether giving a total 19 o~ 350 mg. (73~) of short white needle~, m.p. 168-174 dec.
Anal. Calcd. for C16H13N205Cl: C, 55.05; H, 3.76; N, 8-02;
21 Cl, 10.02.
22 Found: C, 54.65; H, 3.79, N, 8.46; Cl, 10.53.
23 The IR spectrum shows peaks in the carbonyl region at 24 5.52, 5,60, 5.80 and 5.85~. The NMR spectrum shows peaks at 2.13 (4H), 3.78 (IH,d,J- 4.1 Hz); 4.29 (lH,d,J= 4.1 Hz), 26 7.67 (3H), 7.69 (3H). The u.v. ~pectrum shows ~ EmaH
27 236 (7400), 296 (1800).
28 The compound has the ~tructure~

3o . 1~18~20 2 ~ N

6 Conversion pf _he Acid to the Methvl Ester ? The acld ~200 mg., 0.57mmole) wa~ dlssolved in 30 ml. of 8 a 1:1 mixture of methylene chloride and ether. The solution was 9 cooled and treated wlth excess ethereal diazomethane. Th~
10 ~olutlon which resulted was stirred for 0.5 hour~ allowed to 11 warm to room temperature during an additional 1 hour, and then 12 evaporated at 40 to a white crystalline residue. Recrystallization 13 ~rom a mixture of chloroform and petroleum ether gave 0.20 g.
14 (97~) of oolorles~ fine needles, m.p. 178-180 dec.
The compound has the structure 17 ~ N ~ ~

19 O C2Me r 1 Converslon of The Acid Chloride to the MethYl Ester 2 The crystalline acid chloride (500 mg., 1.4~ mmoles) was dl~solved in methylene chloride (10 ml.) and absolute methanol 4 (10 ml.) was added. The mixture was stirred at room temperature for 30 minutes, then diluted with methylene chloride (50 ml.~
6 and washed succe~sively with ice-cold 5~ bicarbonate solution 7 (10 ml.) and water. After drying over anhydrous magnesium 8 sulfate and removal of the solvent a crys~alline residue was g obtafned. Th$s wa~ recry~tallized from methylene chloride -petroleum ether to give 463 mg. (93~) of methyl ester identical Sl to that de9cribed above.
12 Anal- Calcd- for Cl~ 15N205Cl C, 56-3; H~ 4-16; N~ 7-71;
1~ Cl, 9.78.
14 Found: C, 56.58; H, 4.37; N, 7.55; Cl, 9.82.
Ihe NMR spectrum shows peaks a~ 2.10 (m,4H), 3.77 16 (lH,d,J~4.1 ~z), 4.23 (lH,d,J-4.1 Hz), 6.18 (3H), 7.57 (3N), 17 7.66 (3H).

19 ~ Converslon of AnhYdro-6-Phthalimldo~enlclllin Into ~ ~ixture o~ Methvl 2-(2~R-chloro-3~S-~hthallmido-4~-oxo)- -azetidinYl-3-meth~1-2-butenoate and its 2'S e~imer Chlorine gas was passed at room temperature into a solutlon o~ anhydro-6-phthalimldopenicillin (1.0 g., 3.04 mmoles) in methylene chloride (30 ml.). After 3 min. the ga~ introduction 2~
was terminated and, after an addltional 5 min. the solvent 6 was removed under reduced pressure at ~0. The solid re~idue was redls801ved in methylene chlorlde (20 ml.) and absolute methanol (20 ml.) was added. This solution was stlrred at room temperature for 30 min. and then e~aporated to drynes~

under reduced pressure at 40. The residue was cry~tallized 3o .. ,, .. . ,, . . . ~

~ 20 1 from chloroform-petroleum ether to give 600 mg. (55~) o~ the 2 ester having the 2'R-ohloro configuration. The mother liquor was 3 chromatographed on a 1.5 x 1~ cm column of alumina (Woelm, grade II).
4 Elutlon with 1:1 methylene chloride - benzene af~orded 202 mg.
(18%) of a new compound ln the ~irst 25 ml., ~ollowed b~ 93 mg.
6 of a mlxture of the 2'R-ester and the new compound in the 7 next 25 ml. Elution wlth methylene chlorlde (40 ml.) then 8 ar~orded an additlonal 68 mg. of the 2'R-ester.
9 The new compound was crystallized from methylene chloride-10 petroleum ether to give the ester having the 2~S-chloro con~iguration, 11 m.p. 192-194.

13 Anal- Calcd- for C17H15N25Cl C, 56-3; H~ 4-16; N~ 7-71;
14 Cl, 9.78-Found: C, 56.42; H, 4.43; N, 7.68; Cl, 9.60.
16 m e NMR spectrum shows peaks at 2.17 (4H,m), 3.77 (lH,d,J=
7 2.0 Hz), 4.4 (lH,d,J= 2.0 Hz), 6.17 (3H) J 7.7 (~H), 7.92 (~H).

19 The ~tructure of this compound i~

2~ ~\r -1 Stereo~electivlt~ of the Chlorination of Anh,Ydro-6-2 Phthalimido~enlclllln 3 Anhydro-~-phthallmldopenlclllin (0.5 g., 1.52 mm~les) 4 wa~ chlorinated ln methylene chlorlde, as already described.
The NMR ~pectrum o~ the total product ~howed pe~k~ at 2.12 6 (~H,m), 3.78 (0.6H,d,J=4.2 Hz), 3.77 (o.4H,d,J=1.8 HZ)J 4.25 7 (0.6H,d,J=4.2 Hz), 4.3~ (0.4H,d,J=1.8 Hz), 7.57 (1.8H), 7.65 8 (1.2H), 7.68 (1.2H), 7.77 (1.2H).
9 The chlorlnatlon reaction i~ therefore 3tereo~elective 10 under these condltions, a 60:40 mlxture of the 2'R-chloro:
11 2~S-chloro eplmers being obtalned under these conditions.
12 Cry~talllzatlon of the product from methylene chloride-13 petroleum ether a~forded 300 mg. (38%) o~ the pure dlchloride 14 havlng the 2~R-con~lguration. The mother liquor wa~ then 15 dl8solved ln ab~olute methanol (10 ml.) and the ~olution allowed 16 to stand ~or 30 mln. at room temperature with occa~ional shaking.
17 It was then dlluted with methylene chlorlde and wa~hed succe3sively 18 with lce-cold ~odium blcarbonate solution and water, and dried over 19 anhydrou~ magneslum sulfate. Evaporatlon o~ the solvent gave 20 a residue whose NMR spectrum showed it to be a 1:2 mixture of 21 21R- and 2~S-methyl esters. Thi~ was chromatographed on alumina 22 (Woelm; grade II), elutlon with 1:1 benzene-methylene chloride 2~ a~orded 120 mg. of the 2'S-methyl e~ter in the flrst 10 ml. o~
24 eluate, followed by mixture of the 21R and 2tS ester~. The ~ir~t

25 eluate wa~ crystallized from methylene chloride-petroleum ether

26 to give 55 mg. (7~) of pure 2~S ester.

27 `

1 In a second experlment the chlorination was performed for 2 3 mln., as already de3cribed and the solution allowed to ~tand 3 at room temperaturè for ~ hr. Evaporatlon then afforded a -4 mixture containing 6~% o~ 2-(2'S-chloro-3~S -phthalimido-4~_ oxo)azetidinyl-3-methyl-2-butenoyl chloride and ~2% of the 2'R
6 epimer, i.e., under these condition~ the ci~:trans ratlo was 7 revised ln favor of the trans i~omer~ The same 68:32 ratlo 8 was obta~ned i~ chlorlnation was performed for 30 ~econd~ and 9 the solution immediately evaporated to dryness.
~hen chlorlnatlon was perPormed for 10 second~ with a lL ~low ~tream o~ ¢hlorlne, and the mixture then lmmediately evaporated 12 to drgne~, a slngle new compound was obtalned. The NMR spectrum 1~ o~ thls new ¢ompound showed peaks at (CDC ~ 2.1 (4H,d), 4 01 (2H "), 14 7.60 (~X), 7.64 (3H). In CD3COCD~ the two-proton slnglet at 4.01 15 ~howed ~llght splitting to a doublet. The compound is as~igned 16 the gtru¢ture, ~ J ~
21 Cl COSCl 2~ m at it i8 an lntermediate ln the chlorlnation of the anhydro-24 peniclllln was shown by it~ conversion, upon further chlorlnation 25 to the 2'R and 2'S dichlorldes, ~r

28

29 Equilibration of methyl 2-(2'R-chloro-3'S-phthalimido-4'-oxo)-azetidinyl-,-methyl-2-butenoate and its 2'S epimer A. Starting with the 2'R isomer.
The pure 2'R ester (100 mg., 0.28 mmole) was added to a warm solution of tetraethylammonium chloride (95.2 mg., 0.57 mmole; two molar equivalents) in acetone (15 ml.). The solu-tion was refluxed for 2 hours, and then cooled to room temper-ature and poured onto a mixture of water and ice. Extraction with methylene chloride, followed by washing of the extract with water, drying over anhydrous magnesium sulfate and evap-oration afforded a crystalline residue. The NMR spectrum of this residue was identical to that of the starting material except for the appearance of a weak doublet at r4.4 (J=2 Hz).
The substance was therefore redissolved in acetone containing tetraethylammonium chloride (95.2 mg.), and refluxing was continued for an additional 14 hours. Isolation in the same manner as described above afforded a residue whose NMR spec-trum showed it to be a 1:1 mixture of 2'R and 2'S esters.
The experiment was repeated with 100 mg. (.28 mmole) of the pure 2'R ester and 238 mg. (5 molar equivalents) of tetraethylammonium chloride in methyl ethyl ketone (10 ml.).
After 4 hours of refluxing the product was isolated and found to be a 3:2 mixture of 2'R and 2'S esters. This ratio did not change when the matérial was refluxed for a further 8.5 hours in methyl ethyl ketone containing 5 molar equivalents of tetraethylammonium chloride.
The experiment was repeated with 100 mg. of the pure 2'R ester in acetone (15 ml.) containing 5 molar equivalents of tetraethylammonium chloride. After 12 hours and after 24 hour~ reflu~ing a 3:2 2'S:2'R ratio of esters was observed.
The product of a 12 hour reaction was chromatographed on alumina ~, 1~ 18420 1 (Woelm, grade II) Elutlon wlth benzene-methylene chloride (1:1), 2 as already de~cribed, a~orded 40 mg. of the 2~S compound in the 3 rlr~ 25 ml. followed by ~4 mg. oP the 2~S compound in the next 4 45 ml. of eluate.
After 6 hours in refluxing chloroform (~0 ml.) containing 6 5 molarlequivalent~ Or tetraethylammonium chloride, the 21R ester 7 (430 mg.) wa3 converted into a 2:1 2'R:2'S mlxture.

B. Startin~ wlth the 2~S isomer 11 The 2~S ester (40 mg.) wa~ re~luxed for 12 hours in a mi~ture Or acetone (10 ml.) and methylene chloride (5 ml.) 13 contalnlng 2 molar equlvalents of tetraethylammonium chloride.
14 The product wa~ a 1:2 2~R:2~S mlxture.

-47~

... . . . . . . . . . . . .

.

l Chlorination of Anh~dro-6-Phthalimido~enicillin ln the 2 Presence o~ ~etraeth~lammonium Chlorlde 3 A solution o~ anhydro-6-phthalimidopenlcillln (lO0 mg., 4 0.30 mmole) in methylene chloride (5 ml~) containin~ tetra-ethvlammonlum chloride (252 mg. 5 molar equivalent3) was 6 chlorinated ln the usual manner. Evaporation of the solvent 7 then gave a resldue which consi~ted of a ~:2 mixture of 2'S:
8 21R dlchlorides.
9 The experiment was repeated using lO ml. of methylene ¢hloride for the reaction. After removal of the solvent, ll absolute methanol (5 ml.) and methylene chloride (5 ml.) were 12 added and the mixture was stirred for 30 min. Then it was 13 washed wlth ~ce-cold sodium blcarbonate solution and water, 14 drled over magnesium sulfate, and evaporated. The residue (1~2 mg,) was a l:l mixture o~ - methyl esters.
16 Thu8 chlorinatlon Or the anhydropenlcillin ln the presence 17 of added chloride ion~ cau~es a slight lmprovement in the 2~S:-18 2l~ ratlo.
i9 ,' ._ __ . _ ... . . . .. .

4~0 1 Attempted Reaction o~ 2-(2'R-chlor~ h~llmido-4'-oxo~-2 azetidln~ meth~1-2-butenoic acid w~th sod~um azlde.
3 The 2~R acid (50 mg., 0.14 mmole ) was added to a solution 4 o~ sodium azlde (10 mg., 0.15 mmole) in water (10 ml.). Complete dissolution was achieved upon addition of a few drops of 5~
6 bicarbonate ~olution. The solution was heated on the steam bath 7 for 4 hours, by which time it was dark orange in color. After 8 coollng, the solution was brought to pH 4 with N HCl and extracted 9 wlth methylene chloride. The extract was washed with water, dried 14 over anhydrous magnesium sulfate and evaporated to yield 24 mg.
11 of material. The IR spectrum of this material showed no ~ lactam 12 absorption at 5.6~
13 In a second experlment, a solution of sodium azide (20.5 mg., 14 0.~3 mmole) in dimeth~lformamide (30 ml.) wa3 prepared by brie~
warming on the steam bath, and the 2~R acid (100 mg., 0~29 mmole) 16 wa~ added. The resulting solution was heated on the steam bath 17 ~or 19 hours, then cooled, diluted with water, brought to pH 4 18 with N HCl and extracted with methylene chlorlde. After washing 19 w~th water and drying over anhydrous magnesium sulfate the methglene chloride was evaporated to a residue of 47 mg. A smail 21 amount o~ crystalline materlal was obtained upon treatment of this 22 resldue with methylene chloride-petroleum ether. The IR spectrum 23 o~ thl5 material showed no azide peak at 4.7JU and only phthalimldo 24 ab~orption at 5.62~u. Evaporation of the mother liquor gave a resldue whose IR spectrum showed a weak azide peak at 4.7 ~ and 26 ~ome ~-lactam absorptlon at 5.60ju.

3o / ~ i 1 Converslon o~ methYl 2-(2~R-chloro-3~S-~hthalimldo-4~-oxo)-2 azetldln~ -methvl-2-butenoate into meth~l 2-(2'S-azldo-~'S-3 ~hthallmido-4~-oxo~azetldlnvl-3-methvl-2-butenoate, ~ Sodlum azide (10.1 mg., 0.16 mmole) was dl~solved in DMF
(15 ml.) by brief warmlng on the steam bath, and to this solutlon 6 wa~ add!ed the methyl ester having the 2'R-chloro con~iguration 7 (50 mg., 0.14 mmole). The resultlng solution was 3tirred at 8 room temperature for 24 hours and then dlluted wlth water and 9 extracted with methylene chloride. The methylene chloride extract was washed thoroughly with water, drled over anhydrous magnesium 11 sulfate and evaporated to dryness. ~he resulting whlte crystalline 12 solid wa~ recry~tallized ~rom chloroform-petroleum ether to glve 13 42 mg. o~ unreacted 21R ester.
14 In a seoond experiment the reaction mixture was heated on the 8team bath ~or 5 hour~, by which time the color had become a deep 16 ~ellowish-orange. Isolatlon o~ the product as described above ~7 a~rorded 38 mg. o~ a solid residue whose IR spectrum showed aælde 18 absorption at 4.7~ and carbonyl peaks at 5.58, 5.62, 5.79 and 5.82)u.
19 The NMR ~peotrum showed, in the ~-lactam region, l-proton absorptions at 4.22 and 4.71 (d,J-2.0).
21 In a thlrd experiment, sodium azlde (20,2 mg., 0.~1 mmole) was 22 dl~olved ln 10 ml. o~ ~reshly distilled DMF, the 2'R ester (100 mg., 23 0.28 mmole) was added, and the solution was heated 5 hours on the 24 steam bath. The product was i~olated in the usual manner and wa~
cry~tallized from 2-~utanone- ethanol to gi~e 25 mg. of 2~S-azido 26 e~ter (~irst crop), m.p. 142-144, 27 Anal Calcd- for C17H15N55 C~ 55-29; H~ 4 09; N~ 18-97 28 Found: C, 55.45; H, 4.02; N, 18.68.

~5~

- - ;

1 The NMR spectrum ~hows peak~ at 2.22 (4H,d), 4.22 (lH,d,J=2.0 Hz), 2 4.71 (lH,d,J=2.0 Hz), 6.17 (3H), 7.70 (3H), 7.91 (~X).
3 The structure of thç compound is O
~ ~ ~N3 8 C02Me In a further experiment sodium azlde (20.2 mg., 0.28 mmole) li was dissolved in fre~hly distilled D~F (10 ml.) by heating on 12 the steam bath for 0.5 hours. Then the 2'R-chloro ester 13 (100 mg., 0.28 mmole) was added, followed by an additlonal 14 20.2 mg. of sodium azide. The resulting mixture was heated at 90 for 3 hours, with stirring. Isolation a~ described above 16 gielded a semi-solid residue which weighed 68.2 mg. (67%) and 17 whose NMR spectrum was identical to that descrlbed above.
18 Chromatography on a lx2 column of alumina (Woelm, grade II) 19 and elutlon with methylene chlorlde afforded 62 mg. of crystalline material. Recrystallization from methylene chloride-21 petroleum ether afforded 38 mg. in the first crop, m.p.
22 144-145 (colorle~s prisms).

2~

1 Conversion of methvl 2-(2'S-chloro-~'S-~hthallmldo-4'-oxo~-2 azetldlnvl-~-methvl-2-butenoate lnto methvl 2-(2'R-azldo-~'S-3 ~hthallmldo-4'-oxo)azetldln~1-3-meth~1-2-~utenoate.
4 The pure 2'S-chloro ester (100 mg., 0.28 mmole) was reacted wlth ~odlum azlde t2 molar equlvalents) ln DMF (10 ml.) as ln 6 the las!t experlment descrlbed above. Isolatlon ln the same 7 manner af~orded 52.2 mg. of materlal. This material was 8 chromatographed on a 4.5 x 1 cm column of alumlna (Woelm, g actlvlty II). Elutlon wlth methylene chlorlde afforded no material ln the flrst 10 ml. ~ollowed by 13.0 and 11.1 mg.
11 Of crg8talllne materlal ln each o~ the next 10 ml. Both re~ldues 12 had the same N~ spectrum. m ey were therefore comblned and 13 recry~talllzed ~rom chloro~orm-petroleum ether to glve 19 mg.
14 0~ co~orles~ needles, m.p. 183-187 dec.
The NMR ~pectrum show~ peak~ at 2.10 (4H,d), 4.18 16 ~lH,d,4.0 Hz), 4.33 tlH,d,4.0 Hz), 6.10 (3H), 7.47 (6H).
17 Anal. Calod- for 17 15 5 5 ' 55 18 Found: C, 55.o6; H, 4.25; N, 19.10.
19 The ~tructure of thls compound i~

22~

3o _ .. , , .. . . . . _ .... . .

~ J

2 Chlorination of the p-toluenesulfonic acid salt of anhydro-6-3 aminopenicillin.
4 The salt (~28 mg., o.8g mmole) was suspended in methylene 5 chloride (30 ml.), the mixture cooled to 0, and gaseous chlorine 6 Wa8 i~troduced for 15 seconds. Dry nitrogen was then passed 7 lnto the resulting yellow solution for 15 minutes to remove 8 excess chlorine, and the solution was evaporated to dryness.
9 Trlturatlon of the residue with dry ether afforded a quantita-tive yleld of the mixture of two compounds shown below:

112 TsOH-H2N ` ~ Cl T8OH H2N~ ~ IICl ~OCl ~ ~COCl 2'R-isomer- 2'S-isomer 16 m e mlxture was a stablé (below 20) white powder, m.p.
1~ 148-149 dec. The IR spectrum showed peaks at 5.55 and 5.62 ~ .
~8 The 2~R-lsomer (formed in 80% yleld) showed NMR absorption 19 (CDC13) at ~ 2.20 (2H,d), 2.80 (2H,d) 4.02 (lH,d,4.2Hz), 4.82 (lH,d,4.2 Hz), 7.63 (3HJ, 7.80 (3H), 8.oo (3H). ~he ~ pro-21 tons were not observed.) The 2'S-isomer (~ormed in 20% yield) 22 showed NMR ab80rption at 2.20 (2H,d), 2.80 (2H,d), 4.82 (2H,m), 23 7.63 (3H), 7.83 (3H), 8.oo (3H).
24 Chlorination of anhydro-6-tritylamino penicillin, the precursor of the p-toluenesulfonic acid salt, was unsuccessful 26 uslng C12, S02C12, pyrrolidone hydrotrichloride, pyridinlum 27 trlchloride, PC15, and (C6H50)~PCl . In each case a reaction 28 of the desired type occurred, but the trityl group was then lost 29 and the product decomposed.
3 Chlorination of the p-toluenesulfonic acid salt in the ~53~

~ 34ZO

1 presence o~ excess tetraethylammonium chloride did not alter 2 the ratio o~ the 2'R and 2'S isomers.

4 Reactlon Or the chlorination product of the ~-tolu~nesul~onic acld salt o~ anh~dro-6-amino~enicillin with metha~olO
6 The anh~dropenicillin salt (3.80 g., 10.~ mmoles) was SU8-7 pended ln methylene chloride (150 ml.), the mixture was cooled 8 to -5, and a 910w stream of dry nltrogen wa~ passed through it.
9 Gaseous chlorlne was pas~ed lnto the mixture for 30 seconds, and ~ the nitrogen stream was then continued for 15 min. Methanol -11 (75 ml.) was added and the resulting yellow solution was swept 12 wlth nltrogen at 0~for 20 min. m e cooling bath was then 13 removed and, a~ter 15 min., the ~olvent was removed under reduced 14 pressure at 25. m e residue was treated wlth 5 ml. o~ methylene chloride and the resulting solution re-evaporated; this procedure 16 wa~ repeated three times and at this point the pale yellow foam 17 had no odor of chlorine or HCl. The ~oam was dis301ved in dry acetone, the orange solution was ~iltered to remove a small 19 amount of insoluble material, and petroleum ether (~o-60) was added to the cloud point. A ~ew drop~ of acetone were then 21 added to clarify the solution, and crystallizatlon wa3 allowed 22 to proceed at 10 C. The white crystal~ thus obtained were 23 washed with cold 1:1 acetone-petroleum ether, and dried in vacuo.
24 me y~eld was 2.7 g. (67%), m.p. 125-130 dec. The compound has the structure ~hown 26 ~ H
27 T~OH .H2N~C
28 ~ h ~

-54~

r 3420 ~' 1 Anal. Calcd. for C16H21N206Cl: C, 7. ; , 5 2 Found: C, 47.6?; H, 5.54 3 The NMR ~pectrum shows peaks at 2.22 (2H,d), 2.90 (2~,d) 4 4.02 (IH,d,4~0 Hz), 4.87 (lH,dJ4.0 Hz), 6.48 (3H~, 7 65 (3H), 7.78 (3H), 8.15 (~H).
6 l 7 Interaonversion of the meth~l ester~ o~ the 2'~-ahloro-3'S-8 amlnotos~late and 2'R-chloro-~l_-phthalimido serie~.
g The crude methyl ester obtalned by chlorination of 193 mg.
(o.48 mmole) of the p-toluenesulfonic ac~d ~alt o~ anhydro-6-11 amlnopenicillin, and then treatment with methanol, wa~
12 di~olved in methylene chloride. The solution was cooled 13 to 0 C and shaken with an ice-cold 5~ sodium blcarbonate 14 ~olutlon. The colorles organic layer wa~ dried over anhydrous magnesium sul~ate, the volume reduced to 5 ml., and N-carbo-16 ethoxyphthalimlde (100 mg., o.46 mmole) was added. The 17 reaction mixture was allowed to stand overnight at room 18 temperature and the solvent was then removed. Theresidue was 19 ¢hromatographed on a column of Woelm alumina (neutral, grade II3.
Elutlon wlth 1:1 benzene-methylene chloride afYorded 37 mg. of 21 unde~ined material ~ollowed by 68 mg. (after recrystallizatlon 22 ~rom ¢hloro~orm-petroleum ether) o~ the methyl ester o~ 2-(2IR~
23 chloro-~'S-phthalimido-4'-oxo)azetldlnyl-~-methyl-2-butenoic acid, 24 identlaal in all re~pects with the compound obtained from anhydro-6-phthallmidopenicillin.
26 The reaction sequence ~ust descrlbed i~:

~0 .. . . .

2 , _ _ ~Cl H H=~Cl 3 T80H H2Nr~ ~ NaHC03 H2N~
4 0~

8 ~N C2C2N5 o 11 > C2CH3 .... _ _ _ .... . .... . .. . ... ..

13~1~420 1 Hvdrolvsis of the chlorination ~roduct of the ~-toluenesulfonic 2 acld salt of anhvdro-6-amino~enlcillin 3 The salt (200 mg.) w~s chlorinated in the usual way and, 4 after removal of the solvent, the residue was maintained under hlgh vacuum ~or 30 min. It was then dissolved in a mixture o~
6 D20 (2 ml.) and CD3COCD~ (2 ml.), cooled to 0, and the NMR
7 spectrum wa~ recorded at intervals. Hydrolysi~ was complete 8 after ~ hr., and the solvent was, therefore, removed by g l~ophilization. The resulting foam was redissolved in D20.
The NMR spectrum of this solution indicated that quantitative 11 conversion to a 4:1 mixture o~ 2'R:2'S chloro acids had been 12 achleved.

5T~OH-H2N ~ Cl TSOH H2N ~ Cl 160 /~ ~ D20-CD3C~CD3~ L 1 J ~
17 COCl COOH
18 2 'R- chloro acid 20H ~ ~Cl H H Cl TsoH H ~ ~ TsOH H2 ~ '"`
22 0 ~ N ~
23 COCl OOH
24 2'S~hlcro acid The2 'R-chloro acld showed NMR absorption~ at 2.37 (2H,d), 2.78 26 (2H,d), 3.78 (lH,d,4.0 Hz), 4.93 (lH,d,4.0 Hz), 7.77 (~H), 27 7.88 (3H), 8.og (3H). The epimerlc 2 'S-chloro acid had NMR
28 ab~orption at 2.37 (2H,d), 2.78 (2H,d), 4.53 (lH,d,2.0 Hz), 29 4,57 (lH,d,2 0 Hz), 7,77 (7H ), 7.98 (3H), 8.24 (3H).
~0 ~57~

- ~ ) ~18420 2 Methyl ester of the 2-(2'~-chloro-~'S-amino-4'-oxo3azetidin~1-.
3 3-meth~1-2-butenolc acid.
4 The methyl ester of the 2'R-chloro-3'S-amlnotosylate was neutralized with bicarbonate, as already described. Evapora-6 tion of the methylene chloride solution ga~e the free base~
7 a crystalline compound, m.p. 67-70 dec. The compound 8 was not stable ln the solid state and darkened percept~bly g after 10 minutes at room temperature.
m e NMR spectrum of the compound has peaks at 3.97 (lH,d, 11 4.1 Hz), 5.38 (lH,d,4.1 Hz), 6.22 (3H), 7.70 (3H), 8.oo (3H).
12 The posltion of the ~ protons ~aries with time; although 13 these peaks shift, no other changes occur in the spectrum.
14 The IR spectrum of the co~pound has peaks at 2.94, 5.60, 5.80, 6.12~ which (in CH2C12) do not change with time.
16 The structure of this compound is H2N~
18 ~ I ~ ~

,) J
342~

2 Methyl ester of 2-(2'~-chloro-3'-S-amino-4'-oxo)azetldinyl-3-_ _ _ 3 methyl-2-butenoic acid by eplmerization cf the 2'~-compound.
_ _ .
4 The 2'R-chloro-3'S-aminotosylate (440 mg., 1.09 mmole) and tetramethylguanidinium chloride (1.387 g., 9.1 mmoles, 6 9 molar equivalents) were refluxed in spectroscopic grade 7 chloroform (9 ml.) for 4.5 hours. The solut~on was then 8 cooled to 0, washed with ice-cold 5% bicarbonate solution, g dried over anhydrous magnesium sulfate, and evaporated to dryness under reduced pressure at 25. The NMR spectrum of 11 the residue indicated it to be a 5:1 mlxture of the 2'S- and 12 2'R-epimers, the predominant isomer being the 2'S compound, 13 whose structure is:

~ N ~ ~C1 16 o ~C02cH3 18 The NMR spectrum of this compound shows peaks at 4.45 (lH,d,1.8 19 Hz), 5.63 (lH~d,1.8 Hz), 6.18 (3H), 7.70 (3H), 8.oo (3H)- The position of the NH2 protons depends upon the age of the solu-21 tlon.
22 Complete separation of the two epimers could be achieved 2~ by alumlna chromatography and elution with 1:1 benzene-ethyl 24 acetate. However, because of the instability of these com-pounds it was usually more convenient to separate at a later 26 stage 2'7 ~59-~ 42~

2 Conversion of the p-toluenesulfonic acld salt of methyl 2-(2'~-3 chloro-3'S-amino-4'-oxo)azetldinyl-3-methyl-2-butenoate to the 4 2'~-azido-3'~-amino ester.
5. me crystalline methyl ester having the 2'R-chloro-3'S-6 TsOH.H2N- config~ration (448 mg., I.l mmoles) and tetra-7 methylguanidinlum azide (347 mg., 2.2 mmoles, 2 molar equiva-8 lents) were refluxed for 75 minutés in 20 ml. of anhydrous g chloroform. The solution was allowed to cool and excess an-hydrous ether was added to precipitate tetramethylguanidinium lI chloride, which was removed by filtration. The-resultlng 12 material, after removal of the solvent, was the desired 2'S-13 azldo-3'S-amino ester (237 mg., 90%) which appeared pure by 14 t.l.c. and NMR. The NMR spectrum had peaks at 4.97 (lX,d, 1.8 Hz), 5.87 (lH,d,1.8 Hz), 6.20 (3H), 7.00 (2H), 7.72 (3H), 16 8.02 (3H)-U me compo~nd has the structure 18 H~N~ N3 19 - ~ N

22 The compound could also be isolated by washing the chloro-2~ form reaction mlxture with cold water, drying and evaporating.
24 Tetraethylammonium azide (in various solvents) and sodium azlde (in DMF) were less effectlve for this reaction.

.

2 Conversion of the p-toluenesulfonic ~cid salt of methyl 2-(2'S-3 ch~P ro-3'~-amino-4'-oxo)azetidinyl-3-methyl-2 -butenoate to the 4 2'~-azido-3'S-amino methyl ester.
A 4:1 mlxture of 2'S- and 2'R-chloro-3'S-amino esters from 6 an epimerization of the 2'R-chloro compound (532 mg., 2.29 7 mmoles), and tetramethylguanidinium azide (500 mg., 3.2 .8 mmoles) were refluxed in pure chloroform (10 ml.) for 4.5 9 hours. The mixture was then washed ~rith ice-cold 5% bicar-bonate solution, dried over anhydrous magnesium sulfate, and 11 evaporated to give 465 mg. (85,~) of a 3.3:1 mixture of 2'R-12 and 2'S-azido-3'S-amino methyl esters. This mixture was 13 separated by chromatography on neutral alumina (Woelm, 14 activity II). Elution with benzene:ethyl acetate (2:3) a~forded the pure 2'R-azido-3'S-amino ester as a crystalline 16 compound. Recrystallization from chloroform~petroleum 17 ether gave long needles, m.p. 116-117.
18Anal. calc'd. for CgH13N503: C, 45.19; H, 5.48, N, 29.28.
19Found: C, 45.42; H, 5.24; N, 28.81.
20The IR spectrum has peaks at 4.72, 5.62 and 5.80~u. The 21 ~ spectrum shows peaks at 3.97 (lH,d,4.1 Hz), 4.38 (d,4.1 22 Hz), 6.22 (3H), 7.60 (2H), 7.70 (3H), 8-oo (3H)-2~ me compound has the structure J_~J
26 O ~ COOCH;~

2~

~ 3420 1 Se~aration of the 2'S- and 2'~-azido-3'S-amino methyl esters D
2 via the ~-toluenesulfonic acid salts.
3 A 1:1 mixture of the 2'S- and 2'R-azido compounds (239 mg.) 4 was dissolved in dry acetone (3 ml.) and the solution was treated with an equivalent amount of p-toluenesulfonic acid 6 hydrate. Crystallization began after 5 min. After 15 hr., 7 acetone (1 ml.) was added and, after an additional 20 min., 8 ether (5 ml.). Filtration then gave 150 mg. (72% recovery, 9 based on one isomer) of a crystalline p-toluenesulfonic acid salt. Regeneration of the free base (NaHC03-H20-CH2C12) 11 revealed that this was the salt of the 2~S-azido compound.
12 The separation procedure is thus 14 H2N ~ 3 H2N ~ ~N3 6 o~ L J~ o ~

18 ~sOH.H20 sON.H2~ q'sOX H

24 OOCH~ OOC~
less soluble more soluble ,0 PhenylacetylatiQn of Methyl 2-(2~R-chloro-3'$-amino-4'-oxo~-azetidinyl-3-methyl-2-butenoate.

The free 2'R-chloro-3~'S-amino ester, obtained from 722 mg. (1.78 mmoles) of the p-toluenesulfonic acid salt, was dissolved in methylene chloride (15 ml.), and phenyl-acetic acid (242 mg., 1.78 mmoles) was added. This solution was treated, dropwise with stirring, with a solution of di-cyclohexylcarbodiimide (405 mg., 1.96 mmoles). Precipitation of dicyclohexylurea commenced before the addition was com-plete. The reaction mixture was allowed to stand at room temperature for three hours, by which time no free amine re-mained (by t.l.c.). Most of the urea was then removed by filtration, and the filtrate was washed with ice-cold 5~
bicarbonate solution. After drying over anhydrous magnesium sulfate, the organic phase was evaporated to give a solid residue. This was dissolved in boiling chloroform and an equal volume of petroleum ether (30-60) was added, whereupon crystallization occurred. The crude product weighed 700 mg.
One more recrvstallization from the same solvent mixture gave 500 mg. (80%) of methyl 2-(2' = chloro-3'S-phenylacetamido-4'-oxo)azetidinyl-3-methyl-2-butenoate, m.p. 111-115 dec. The NMR spectrum of this compound shows peaks at 2.62 (5H), 3.10 (lH,d,10 Hz), 3.94 (lH,d,4.2Hz), 4.34 (lH,q,4.2,10 Hz), 6.22 (3H), 6.31 (2H), 7.70 (3H), 8.02 (3H). ~he same compound could be obtained, but in slightly lower yield using diiso-propylcarbodiimide or phenylacetyl chloride and triethylamine.
The compound has the structure H H
PhCH2CONH_ I _ fCl ~ N ~

~3 ~ , 2 Phenylacetylation of Methyl 2-(2~S-chloro-3'S-amino-41-oxo)-3 azetidinyl-3-methyl-2-butenoate~Cyclization to Oxazoline.
4 The p-toluenesulfonic acid salt of methyl 2-(2'R-chloro-3'S-amino-4l-oxo)azetidinyl-3-methyl-2-butenoate (651 mg., 1.6 mmoles) 6 and tetramethylguanidinium chlorlde ~1~210 g., 5 molar equiva-7 lents) were refluxed in spectroscopic grade chloroform (9 ml.) 8 ~or 4.5 hours. The resulting solution was cooled~ washed 9 successively with ice-cold 5% bicarbonate, ice-cold saturated sodium chloride, dried over anhydrous magnesium sulfate, and 11 thèn used immediately for the next step (pre~ious experiments 2 had indicated that the above procedure leads to a 5:1 or 6:1 13 excess of the 2'S-chloro-3'S-amino compound over the 2'R-chloro-14 3'S-amino compound). To the solution were added phenylacetic ac~d (?28 mg., 1.7 mmoleS),diisopropylcarbodiimide (222 mg., 16 1.8 mmoles) ana methylene chloride (20 ml.), and this solution 17 was refluxed for 1 hour. Removal of the solvent ga~e a re-18 sidue whose NMR spectrum showed peaks at 2.73 (phenyl), 4.72 19 (d~ 1.9 Hz), 5.33 (d,1.9 X~), 6.30 (OCH3), 6.47 (C~ ), 7.80 (CH3), 8.o5 (CH3). The structure o~ this compound is PhC~ CONH~ ~ Cl 22 ~ ~ ~ ~
23 C02C~3 -6~-~18420 1 The spectrum also showed peaks at 4.02 (d,3.8 Hz), 4.80 2 -~d, 3.8 Hz), 6.33, 7.83, 8.43. This is the spectrum of the 3 compound having the structure, 4 C~2Ph N ~ ~ 0 H ~ IIIH
7 / ~ ~ ~2CH3 9 i.e., 2-benzyl-6-~'-methoxycarbonyl-2'-methylprop-1'-enyl)-1-oxa-3,6-diaza-4S,5R-bicyclo[3,2,0]hept-2-en-7-one, which is 11 formed by intiamolecular cyclization o~ the preceeding compound.
12 The cyclization occurs on standing, but is facilitated by heating 13 of a solution of the chloro compound, by shaking with bicarbonate, 14 or by chromatography on alumina or silica gel of either epimeric 2'-chloro-3'-acylamino ester, as will be described below.
16 Chromatography of the a~ove mixture on silica gel and elu-17 tion w~th petroleum ether - ethyl acetate (1:1) afforded the 18 oxazoline. Recrystallization from ethyl acetate gave 240 mg.
19 (49% from the p-toluenesulfonic acid salt), m.p. 126.5-127.
The NMR spectrum of the pure compound shows peaks at 2.73 21 (5H), 4-02 (lH,d,3.8 Hz), 4.80 (lH,d,3.8 Hz), 6.30 (3H), 6.33 22 (2H), 7.83 (3H), 8.43 (3H).
2~ -~ 3420 Formation of the oxazoline upon chromatography of the cis-2'_-chloro-2'S-phenylacetamido methyl ester.
_ The crystalline cis compound (100 mg.) was chromato-graphed on alumina (Woelm, grade II). Elution with carbon tetrachloridebenzene (1:1) gave 38 mg. of the oxa201ine in the first fractions, followed by uncyclized cis compound.
In a second experiment, the cis compound (1.0 g.) was chromatographed on 37 g. of silica gel, elution being performed with 1:1 petroleum ether (30-60): ethyl acetate. There were obtained in successive fractions 450 mg. of recovered cis com-pound, 140 mg. of a mixture of the cis compound and oxazoline, and 210 mg. of oxazoline. The transformation is PhCN2CON~ ~ cl 12 3 > N ~ Ph In a third experiment the crystalline 2'R-chloro-3', S-amino methyl ester (157 mg., 0.68 mmole), in dry methylene chloride (8 ml.), was treated successively with phenylacetic acid (92 mg., 0.68 mmole) and diisopropylcarbodiimide (93 mg., 0.74 mmole). The solution was stirred at room temperature for 22 hours, and the precipitated diisopropylurea was then col-lected by filtration. Addition of ether to the mother liquor completed the precipitation of the urea. Evaporation of the filtrate, followed by chromatography on a l.Ox7 cm column of alumina (activity II) gave, with 1:1 benzene-methylene chlor-ide, 83 mg. of crystalline material. This was found, by NMR
and t.l.c. to be a mixture of oxazoline and 2'= chloro-3'S-phenylacetamido ester.

4~0 I301atlon of Meth~l 2-~2'R-phenylacetoxy-~'S-phenylacetamido-_r ~
2 4~-oxo)azetldinvl-3-methvl-2-butenoate and oxazoline followinÆ
3 ~hen~lacetvlation Or the e~imeric methvl 2-(2'-chloro-3'S-4 amlno-4'-oxo)azetidln~1-3-meth~1-2-butenoate~.
The p-toluenesulfonic acid salt of methyl 2-(2'R-chloro-6 ~'S-amlno-4'-oxo)azetidinyl-3-methyl-2-butenoate (4.428 g., 7 10.~ mmoles) and 8.260 g. (54.5 mmoles) of freshly prepared 8 tetramethylguanidinium chloride were refluxed for 2 hours in g ~pectroscoplc grade chloroform (65 ml.). The cooled solution 10 was washed successively with ice-cold 5~ bicarbonate solution, 11 lce-cold saturated sodium chloride solution, and then dried 12 over anhydrous magnes$um sulfate. Then a solution of phenyl-13 acetlc acid (1.490 g., 11 mmoles) and diisopropylcarbodiimide 14 (1.500 g., 11.9 mmoles) ln methylene chloride (25 ml.) was 15 added, and the mlxture was refluxed for two hours. The NMR
16 spectrum of the reaction product showed only a small amount of 17 the oxazoline (based on the peaks at 7.83 and 8.43). The solution 18 was then washed with ice-cold 5~0 bicarbonate, drled over anhydrous 19 magneslum sulfate, and evaporated, The NMR spectrum of this 20 residue now showed oxazoline as the ma~or product. Thus, washing 21 wlth bicarbonate had caused cyclization. The product was left at 22 10 overnight, then redissolved in methylene chloride and shaken agaln 2~ wlth blcarbonate solution. After drying and evaporation of the 24 organic layer the NMR spectrum of the residue was redetermined; it 25 now indicated that the mixture contained 70~0 of oxazoline. The 26 mixture, in 1:1 ethyl acetate:petroleum ether, was filtered 27 througb 50 g. of silica gel and then chromatographed carefully 28 on 110 g. of silica gel. Elution was performed with graded 29 mixtures of petroleum ether and ethyl acetate (250 ml. of 20~o

30 ethyl acetate, followed by 200 ml. of ~0~ ethyl acetate, followed ~ 42~

1 by 200 ml. of 30~ ethyl acetate, followed by 200 ml. o~ ~5%
2 ethyl acetate, ~ollowed by 200 ml. of 45% ethyl acetate, followed 3 by 50% ethyl acetate); 40 ml. fractlons were collected. Fractions 4 1-3 afforded 100 mg. of methyl 2-(2'R-chloro-3'S-phenylacetamido-4~-oxo)azetidinyl-~-methyl-2-butenoate. Fractions 5-12 a~forded 6 1.475 g. o~ oxazoline. Fractlons 13-15 were rechromatographed 7 and ylelded, besides an additlonal 150 mg. o~ oxazoline (total 8 1.625 g., 48%), 240 mg. of a compound assigned the structure H H
11 PhCH2CONH~OCOCH2Ph 12 ~ ~ N~

14 C02CH~

16 Thls compound has IR absorption at 2.9, 3.0, 5.60, 5.70, 5.80, 5.98, 6.o5, 6.65~t. The NMR spectrum has peaks at 2.65-2.75 18 (lOH,m), ~.26 (lH,d,9.5 Hz), ~.68 (lH,d,4.1 Hz), 4.57 (q,4.1,9.5 19 Hz), 6.27 (~H), 6.4~ (2H), 6.54 (2H), 7.82 (3H), 8.28 (~H). The 20 mass spectrum shows a molecular ion at m/e 450.

` 1~18420 1 Phenylacetylatlon of meth~l 2-(2'R-azido-~'S-amlno-4-oxo)-2 azetldlnYl-3-methvl-2-butenoate.
3 The crystalline amino azide (415 mg., 1 74 mmole) was 4 dissolved in dry methylene chlorlde (10 ml.) and to thls solution were added, successlvely, phenylacetlc acid (235 mg., 6 1.73 mmole) and diisopropyloarbodiimlde (220 mg., 1.75 mmole).
7 The solution was refluxed for 9 hours, and the ~olvent waæ then 8 removed. The resldue wa~ triturated with cold carbon tetrachlor-9 lde, and the carbon tetrachlorlde-~oluble material (now free of mo~t 10 o~ the dllsopropylurea) was chromatographed on alumlna (~oelm, 11 grade II). Elution with benzene-ethyl acetate a~forded 641 mg.
12 Or pale yellow oll. This was rechromatographed to ~ield 601 mg.
13 (97~) o~ methyl 2-(2'R-azldo-3~S-phenylacetamldo-4~-oxo)azetidlnyl-14 ~-methyl-2-butenoate as long needles, after recry~tallization ~rom 15 car~on tetrachlorlde-petroleum ether; m.p. 102-103. The compound 16 has the structure U
18 H H ~N3 19 Ph~H2CO

21 0~

23 Anal. Calcd. for C17HlgN504: C, 57.13; H, 5.36; N, 19.60.
24 Found: C, 56.76; H, 5.35; N, 19.42.
The NMR spectrum shows peak~ at 2.72 (5H), 3.38 (lH,br) 26 4 57 (lH,d,4.2 Hz), 4.72 (lH,d,4.2 Hz), 6.27 (3H), 6.38 (2H), 27 7.77 (3H), 8.05 (3H).

' ?

1 Phenvlacetvlatlon o~ methYl 2-(2~-azldo-~s-amino-4t 2 azetldin~l-3-methY1 2-butenoate 3 m e amino azide (323 mg., 1.35 mmole) was dissolved ln 4 methylene chlorlde (10 ml.) contalning triethylamlne (110 mg., 1.09 mmole), and phenylacetylchloride (170 mg., 1.1 mmole), in 6 methyl Te chlorlde ~5 ml.), was added dropwlse wlth stlrrlng.
7 After 30 mln., the reaction mixture was wa~hed wlth flve 10 ml.
8 portions o~ water, drled over anhydrou~ magneslum sulfate, and 9 evaporated. Chromatography on alumina (Woelm, actlvity II) and 10 elution with benzene afforded 185 mg. of methyl 2-(2ls-~zido-3'S-11 phenylacetamido-4'-oxo)azetidinyl-3-methyl-2-butenoate as a 12 colorless oll. The compound has the structure:

15PhCH2C0 ~ ~ ~3 16/~L--N~,,/ -19 The NMR spe¢trm ha~ peaks at 2.67 (5H), 3.22 (IH,d,8 Hz), 4.73 20 (lH,d,2.0 Hz), 5.32 (lH,q,2.0,8 Hz), 6.25 (3H), 6.38 (2H), 7.73 21 (3H), 8.00 (3H).
22 The same aompound wa~ obtalned ln 83% yield using phenyl-23 a¢etlc acld and diisopropylcarbodiimide ln methylene chloride.

27 .

~0 420 `-1Conversion of Methyl 2-(2'R-chloro-3'S-phenylacetamido-4'-2 oxo)azetidinyl-3-methyl-2-butenoate lnto methyl 2-(2'~ azido-_ 3 3'~-phenylacetamido-4'-oxo)azetidinyl-3-methyl-2-butenoate.
4Tetramethylguanidinium azide (126 mg., o.8 mmole), in 5, spectroscopic grade chloro~orm (~ ml.), was treated drop-6 wisel with stirring with a solution of the chloride (229 mg., 7 o.66 mmole) in chloroform (5 ml.). When the addition was com-8 plete, the reaction mixture was refluxed for two hours. At g this time no unreacted chloride remained. The reaction solu-tion was washed wlth water, dried over anhydro~q magnesium 1 sulfate and evaporated. The residue was chromatographed on 12 silica gel to obtain 75 mg. of the azide, identical with that 13 described in the preceeding ,experiment.
14The equation for this reaction is:

16 PhCH2CONH ~ ~e2N-C-~Ue2 PhC~2CONH ~ "

18 C02CH3 - C02CH~

~0 ;

1 Preparation of t-butyl 2-(2'R-chloro-3lS-phthalimido-4'-oxo)-. _ 2 azetidinyl-3-methy~2-butenoate and t-butyl 2-(2'S-chloro-3'S-3 ~hthal~mido-4'-oxo)azetidinyl-3-meth~2-butenoate ~y reaction of 4 the anhydro-6-~hthalimidopenicillin chlorination roduct with t-butanol.
6 I A 2:1 mixture o~ 2-(2'R-chloro-3'S-phthalimido-4'-oxo)_ 7 azetidinyl-3-methyl-2-butenoyl chloride and its 2'S epimer was 8 stirred overnight at room temperature in methylene chloride g containing five molar equivalents of t-butanol. Evaporation of the solution then yielded a mixture containing only 15% o~
11 t-butyl esters (based on integration of the t-butoxy peak at 12 8.47 in the n.m.r. spectrum). The conversion lncreased to 13 40~ when the mixed acid chlorides were re~luxed overnight in 14 methylene chloride-t-butanol. Refluxing for 20 hours in t-butanol solvent effected a 75~ conversion to a mixture of 16 t-butyl esters containing the same 2:1 ratio of epimers as 17 the acid chloride precursor. Chromatography on silica gel 18 separated these compounds. The c~s-isomer was obtained as a 19 colorless oil; its n.m.r. spectrum showed peaks at 2.15 (4H), 203.85 (lH, d, 4 Hz ), 4.38 (lH, d, 4 Hg), 7.71 (6H), 8.46 21 (9H)-22The compound has the structure 25~ ~N ~
OOtBu 26 The trans-isomer crystallized on standing. Recrystalliza-27 tion from ethanol gave material meltlng at 170-172. The 28 n.m.r. spectrum shows peaks at 2.29 (4H, d), 3.85 (lH, d, 29 2.0 Hz), 4.55 (lH, d, 2.0 H~), 7.73 (3H), 1-98 (3H), 8-47 (9H)-.. , ~
~118420 1 Anal. Calcd... for C20~ 1N205Cl: C, 59.32; H, 5-2~3 N, 6-91-2 Found: C, 59.05; H, 5.36; N, 6.75.
3This compound has the structure ~ ~ Cl 7 COOtBu 8 Reaction o~ t-butyl 2-(2'R-chloro-3'S-phthalimido-4'-oxo)-9 azetidinyl-3-methyl-2-butenoate with trifluoroacetic acid.
The ester (100 mg.) was dissolved in trifluoroacetic acid 11 (2 ml.). A~ter two minutes at room temperature the solvent was 12 removed under reduced pressure. The residue was recrystallized 13 from chloroform-petroleum ether to give 2-(2'R-chloro-3'~-14 phthalimido-4'-oxo)azetidinyl-3-methyl-2-butenoic acid, identical ~n all respects to the compound prepared by direct hydrolysls of the dichlorlde.

2g ~7~~
,. , 1 Allylic Bromination of Methyl 2-(2'R-chloro-3'S-2 - phthalimido-4'-oxo)azetidinyl-3-methyl-2-butenoate.
3 To a suspension of the methyl ester (100 mg., 0.276 4 mmole) in carbon tetrachloride (7.~ ml.) were added N-bromo-succinimide (108 mg., 0.61 mmole) and benzoyl peroxide (2 m~.).
6 When this mixture was brought to reflux, the ester dissolved;
7 the heat source was then replaced by a 100 watt Photoflood No. 2 8 lamp ahd reflector mounted close to the reaction flask and 9 stirring was continued until the reaction was complete (10 min.).
The resulting suspension was cooled, diluted with a small 11 amount of chloroform, and the precipitated succinimide was 12 removed by filtration. Evaporation of the filtrate gave a 13 white crystalline solid residue whose n.m.r. spectrum showed 14 no absorption in the region of the allylic methyl groups (7-5 to 8.0), but did show succinimide absorption at 7.2.
16 This was removed, in part, by trituration with carbon tetra-17 chloride and methylene chloride, and the total product was then 18 chromatographed on neutral alumina (Woelm, activity II).
19 Elution with methylene chloride afforded a crystalline dibromo compound which, after recrystallization from carbon tetrachloride 21 -petroleum ether, melted at 65-70 dec. and weighed 116 mg.
22 (80%).
23 The compound has the structure O
~ ~ Cl 28 0 ~

3o ~74-Anal. Calcd- for C17H13N2SClBr2 C, 39.22;
2 - H, 2.52; N, 5.38.
3 Found: C, 38.95; H, 2.36; N, 5.40.
4 The n.m.r. spectrum has peaks at 2.13 (4H), 3.80 (lH, d, 4.2 Hz), 4.21 (lH, d, 4.2 Hz), 5.07 (lH, d, 10.2 Hz), 5.23 ~lH, d, 10.9 6 Hz), 5.27 (lH, d, 10.2 Hz), 5.33 (lH, d, 10.9 Hz), 6.11 (3H).
7 The spectrum appears unusually complex because one of the 8 -CH Br groups is cis to the methoxycarbonyl substituent and 9 the other is trans; and, in each -CH2Br group, the methylene protons are magnetically non-equivalent. The i.r. spectrum 11 has peaks at 5.55, 5.62 and 5.79 ~.

13 Allylic bromination of methyl 2-(2'S-chloro-3'S-14 phthalimido-4'-oxo)azetidinyl-3-methyl-2-butenoate.
~5 The compound (100 mg.) was reacted with two molar-16 equi~alents of N-bromosuccinimide in exactly the same manner 17 a~ described above. Chromatography on alumina (Woelm, activity II~
18 and elution with methylene chloride afforded 122 mg. (84%) of 19 the desired compound as a clear viscous oil which appeared homogeneous by n.m.r. and t.l.c. The n~m.r. spectrum shows 21 peaks at 2.08 (4H), 3.62 (lH, d, 1.7 Hz), 4.27 (lH, d, 1.7 Hz~, 2? S.05 (lH, d, 10.0 Hz), 5.36 (lH, d, 10.0 Hz), 5.38 ~lH, d, 23 11.0 Hz), 5.57 (lH, d, 11.0 Hz), 6.04 (3H).
24 This compound has the structure 28 ~ ~ f 29 ~ \CH ~ r CO2C~3 ~75~

-`, 1~ ~8420 l Allylic brominatior, of methyl 2-(2'R-azido-3'S--2 ~henylacetamido-4'-oxo)azetidinyl-3-methyl-2-butenoate.
3 The methyl ester (136 mg., 0.38 mmole), N-bromo-4 succinimide (210 mg., 1.18 mmole, 3-molar-equivalents), and benzoyl peroxide (2 mg.) were heated to reflux in spectroscopic 6 grade carbon tetrachloride; the heat source was then removed 7 and replaced with a lO0 watt Photoflood No. 2 lamp mounted 8 close to the re~ction vessel. The illumination/refluxing 9 was terminated after 9 minutes. The resulting suspension was cooled, filtered, and the reddish fil~rate washed with ice-cold ll 10% bicarbonate solution. The resulting yellow solution was 12 dried over anhydrous magnesium sulfate and evaporated to give 13 143 mg. (77%) of a viscous oil. Chromatography on alumina 14 and elution with benzene, followed by chloroform afforded 29 mg. of material, having the same n.m.r. spectrum as the 16 reaction product, which did not crystallize. This n.m.r.
17 spectrum shows peaks at 2.67 ~5H,m), 3.33 (lH, br), 4.32 18 (1~, d, 4.0 Hz), 4.50 (lH, d, 4.0 Hz), 5.38 (2H, sl.br.), 19 5.63 (2H, sl.br.), 6.17 (3H), 6.18 (2H). The i.r. spectrum 20has peaks at 2.97, 4.71, 5.60, 5.75 and 5.95 ~. The spectra 21 are those of a compound having the structure 22_ - N3 23PhC~2CONH ~ r Br 24~ N ~ Br 1 R~action of methvl 2-(2'R-chloro-~S-Dhthalimido-4'-oxo~-2 azetidinvl-3-methyl-2-butenoate with one molar equivalent of 3 N-bromosuccinimide.
4 A suspenslon of the cis compound (75 mg., 0.207 mmole), N-bromosuccinlmide (36.9 mg., 0.207 mmole) and benzoyl peroxlde 6 (1.5 mg.) in carbon tetrachloride (5 ml.) was heated to refl~x 7 untll a clear solution resulted. The heat source was then 8 removed and the mixture was stirred while being illumlnated 9 with a 100 watt Photo~lood No. 2 amp. After lO minutes the reaation was terminated and the mixture was cooled to room 11 temperature and filtered to glve succinimide (17 mg., 85% of 12 the theoretlcal amount), identi~ied by its me~ting point and 13 infrared spectrum. The filtrate was evaporated to dryness to 14 glve a white solid resldue which, on the basis o~ its NMR spectrum 15 contained a small amount of succinimide and an exactly 1:1 16 mixture of the two possible monobrominated compounds. The solid 17 was chromatographed on alumina to remove the succinimide.
18 Elution with methylene chlorlde a~forded the 1:1 mixture of 19 monobrominated compounds as a white foam (87.5 mg., 96%). The 20 NMR spectrum of this mixture shows peaks at 2.20 (4H), 3.83 21 (0,5H,d,4.2 Hz), 3.87 (0.5H,d,4.2 Hz), 4.28 (0.5H~d,4.2 Hz), 22 4.32 (0.5H,d,4.2 Hz), 5.10-5.88 (2H,m,overlapping AB quartets), 23 6.15 (1.5H), 6.17 (1.5H), 7.55 (3H).
24 The structures of these compounds are 26 ~ ClCX2Br 28 1 0//~ CH3 ~77-r !1842(;~

1 methyl 2-(2~R-chloro-3'S-phthalimido-~-oxo)azetldlnyl-3-2 methyl-4-bromo-tran~-2-butenoate 4 and 5. 0 6 ~ ~ Cl 9 ' C02CH:~

11 methyl 2-(2~R-chloro-~'S-phthalimido-4~-oxo)azetidinyl-~-12 methyl-4-bromo-ci~-2-butenoate.

l Conversion of the cis- and trans-methyl 2-(2'R-chloro-3'S-2 ~hthallmido-4'-oxo)azetidin~1-3-meth~1-4-bromo-2-butenoates 3 to the cis- and trans-methvl 2-t2~R-chloro-3~S'-~hthalimido-4 4'-oxo)azetidlnvl-~-methvl-4-azido-2-butenoates.
m e l:l mixture of monobrominated compound~ (87.5 mg., 6 0.198 m~ole), in spectroscopic grade chloro~orm (3 ml.), was 7 treated with tetramethylguanidlnium azide (34.4 mg., 0.218 8 mmole). A pale yellow color appeared immediately. ~he solution 9 was stirred at room temperature for 3 hours (under these 10 condition~ the 2~-chloro substituent ls ~table) and was then a 11 pale yellow-brown in color. It was diluted with chloro~orm, 12 washed with water, decolorlzed with actlvated carbon and dried 13 over anhydrous magnesium sulfate. ~vaporation o~ the solvent 14 a~forded 83.9 mg. of a white solld residue. Examination o~ thi~
15 residue by t.l.c. showed no unreacted monobrominated compounds.
16 The IR spectrum had peaks at 4.70 (azide), 5.52 (~-lactam), 5.58 17 and 5.79~ (phthalimido), 5.75 (ester) and 6.16~ . m e NMR
18 spe¢trum showed that the azldes had been obtained. It had 19 peaks at 2.17 (4H), 3.78 (lH,d,4.0 Hz), 4.22 (lH,d,4.0 Hz), 20 5.12-5.87 (2H, overlapping AB quartets), 6.12 (3H), 7.58 (3H).
21 Ihe two lsomers apparently have the same NMR spectrum.
22 The ~tructure~ of the~e compounds are O
24 ~ ~CH2N3 ~79~

1~8420 l methyl 2-(2~R-chloro-3~S-phthalimido-4~-oxo)azetldinyl-3-methyl-2 4-azido-trans-2-butenoate 3 and 5.

g N ~ E~

12 methyl 2-(2'R-chloro-3~S-ph~halimido-4'-oxo)azetidinyl-3-methyl-13 4-azido-cis-2-butenoate~

~6 æ
2~

! ;
lP~420 1 Converslon of the cls- and trans- meth~l 2-(2~R-chloro-~S
2 ~hthallmido-4~-oxo)azetldin~ -meth~l-4-azido-2-butenoate~
to the cis- and trans-meth~l 2-(2~R-chloro~ rh~.h~l ~mt ~-4 4~-oxo)azetidinYl-3-methvl-4-amino-?-butenoates.
The mixture o~ azide~ (87.9 mg.) in benzene (10 ml.~, 6 wa~ hydrogenated over Adams catalyst (50 mg.~ at 45 psl 7 ~or 3 hours. The reactlon solution was then diluted with 8 chloroPorm and passed through a pad o~ anh~drous magneslum g sul~ate. ~vaporatlon at 25 a~forded a sticky ~olid resldue.
The IR spectrum showed a peak at 4.7 ~ about hal~ the 11 inten~ity o~ one ln the same position in the s~arting material 12 The NMR spectrum showed peaks due to the azlde and, a~ well?
13 ~ome new peaks. Reductlon was, there~ore, incomplete. The 14 hydrogenation was repeated for an addltional 3 hours at 45 p,~.i, The resultlng mixture wa~ diluted with chloro~orm 16 and passed through a pad o~ anhydrous magneslum sulfate. The 17 black ~lltrate was not decolorized upon flltratlon through 18 "Cellte" or upon ~haking (oP an allquot~ wlth 5% odlum 19 blcarbonate solution. Evaporation at room temperature a~forded a bla¢k solld residue (92 mg.) whose IR spectrum showed complete 2~ dl8appearan¢e o~ the azlde absorptlon and whose NMR spectrum 22 ~howed disappearance o~ the multlplets in the 5-6~ region 23 and appearance o~ new multipletæ in the 7~ reglon. The solld 24 was redissolved ln chloroformJ treated wlth actlvated carbon and pas~ed through a pad o~ anhydrous magneslum sulfate to 26 g~ve a clear colorless solution. Evaporation gave 87 mg. o~
27 a 801id re~idue. The NMR spectrum shows peaks at 2.18 (4H~, 28 3.88 (lH,d,4.1 Hz~, 4.33 (lH,d,4.1 Hz~, 6.90-7.20 (2H,m~, 6.20 29 (3H), 7.67 (1.5H~, 7.70 (1.5H~. The structuresof the amino compounds are ,' ~

2 1¦ H H

'4 ~oo/

6 . C02C~
8 methyl 2-(2'R-chloro-3'S-phthalimido-4'-oxo)azetidinyl-3-gmethyl-4-amlno-tran~-2-butenoate and 13 ~ ~ 3 15C02CH~
16 . . -- .
17 methyl 2-(2'R-chloro-3l S-phthalimido-4'-oxo~azetldln~1-3-18 methgl-4-amino-cls-2-butenoate.

22 : -1 C~cllzatlon of meth~l 2- (2 ~ R-chloro-3 ~ S-phtha limldo-4 ' -2 oxo~azetidinyl-7-methvl-4-amino-tran~-2-butenoate to ~-3 methvl-4-methox~carbon~1-7S-Phthalimido~ -diaza-6S-4 bicvclo [4.2.0] oct-3-en-8-one ~he above m~xture Or amlne~ was recovered unchanged a~ter 6 standing for 16 hour~ at room temperature and a~ter 3 hours 7 refluxlng ln chloroform 8 The mixed amino esters (60.5 mg.~ 0.159 mmole~, in 9 anhydrous t-butanol (10 ml.),were treated with ~reshl~-prepared potassium t-butoxlde (17.8 mg., 0.159 mmole~. The 11 ln1tlally pale yellow solution lmmediately turned dark brown.
12 It wa~ stlrred at room temperature ~or 1 hour and then poured 13 into lce-cold saturated ammonium chloride solution and extracted 14 with chloroform. m e chloro~orm extraot was washed with water, dried over anhydrous magnesium sulfate, decolorlzed wlth activated 16 carbon, and evaporated at 25 to give 60.7 mg. o~ a solid 17 resldue. Thls was chromatographed on a 0.5x4.5 cm column o~
18 1.0 g. Or neutral alumlna (Woelm, activity II~. Elution wlth 19 methylene chlorlde a~rorded 40 mg. o~ solld in the ~irst 5 ml. Thls was rechromatographed on a 0 5x5.5 cm column of 21 1.2 g. Or alumlna. Elutlon wlth 5 ml. o~ 1:1 benzene-22 methylene chlorlde gave 28 mg. of solid material whose IR
2~ spectrum showed only weak absorption at 5.6~ Elution with 24 10 ml. of methylene chloride then gave 8.6 mg. o~ a crystalline compound, m.p. 121-122. The IR spectrum of thl~ compound 26 (KBr) showed peaks at 2.92 (N-H), 5.56 (~-lactam~, 5.62, 5.79 27 (phthallmido~, 5.82 (e9ter)and 6 03~ (C=C~. The NMR spectrum 28 had peaks at 2.25 (4H), 3.87 (lH,d,2.0 Hz~, 4 30 (lH,d,2.0 ~z~, 29 6.23 (3~), 7.70 (2H), 7.88 (3H~.
3 The compound has the structure 1~18420 N~

O ~~ ~ 3 9 The systematic name for the nucleu~ ls 11 ~
1~ , o~,~ .

1,5-diaza-6S-blcyclo [4,2,0~ octan-8-one.

., 1 Reaction of methyl 2-(2'S-chloro-3'S-phthalimido-4~-oxo)azetidinyl-2 3-methyl-2-butenoate with one molar equivalent of N-bromosuccinimide 3 A mixture of the pure trans methyl ester (165 mg., 4 0.455 mmole), N-bromosuccinimide (81 mg., 0.455 mmole) and benzoyl peroxide (4 mg.), in carbon tetrachloride (12 ml), was bro~ght to 6 reflux. The heat source was then removed and replaced with a 100 watt 7 Photoflood No. 2 lamp. Illumination of the stirred reaction mixture 8 was maintained for 15 mins. The suspension was then cooled, filtered, 9 and the filtrate evaporated to a white foam. This was chromatographed on a 0.5 x 13 cm column of 3.0 g of neutral alumina (Woelm, activity I]
11 Elution with methylene chloride afforded 206 mg. of a 60:4~ mixture 12 of mono bromo compounds. The n.m.r. spectrum of this mixture has 13 peaks at 2.17 (4H), 3.73 ~lH, d, 2Hz), 4.37 (lH, d, 2Hz), 5.27-5.65 14 ~2H, m, two overlapping AB quartets), 6.15 (3H), 7.59 (1.2H), 7.82 15 ~1.8H).
16 The structures of these compounds are 17 i 18 ~ ~D~ Cl ~ 0 0~ ~ CH3 22 methyl 2-(2lS-chloro-3~S-phthalimido-4'-oxo)azetidinyl-3-methyl-4-2~ bromo-trans-2-butenoate 2~ and o ~ N ~ ~

29 methyl 2-(2lS-chloro-3~S-pht~alimido-4'-oxo)azetidinyl-3-methyl-4-30 bromo-cis-2-butenoate, 1 Conversion of the cis and trans-methyl 2-(2tS-chloro-3~S-phthalim-do-2 4'-oxo)azetidinyl-3-methyl-4-bromo-2-butenoates to the cis-and trans-3 methyl 2-(2 S-chloro-3'S-phthali~ido-41-oxo)azetidinyl-3-methYl-4-4 azido-2-butenoates.
The 60:40 mixture of monobrominated compounds (205 mg., 6 0.455 mmole), in chloroform 14 ml), was treated with tetramethyl-7 guanidinium azide (79.1 mg., 0.50 ~mole). The solution immediately 8 turned light yellow. It was stirred at room temperature for 4 hrs.
g and then diluted with chloroform, washed ~ith water, treated with lO activated carbon, and dried over anhydrous magnesium sulfate.
ll Evaporation then a~forded 184 mg. of the mixed azides; i.r.: 4.7, 12 5.55, 5.62, 5.79~; n.m.r.: 2.17 (4H), 3.76 (lH, m, overlapping 1~ doublets), 4.40 (lH, d, 2.0 Hz), 5.52 and 5.58 (0.8H, AB quartet 14 Of one isomer), 5.87 (1.2H, br), 6.15 (3H), 7.67 (l.2~, 7.87 (1.8H~.
The structures of these compounds are 7 ~ ~ ~ 2 3 21 methyl 2-(2~S-chloro-3~S-phtnalimido-4 -oxo)azetidinyl-3-methyl-4-22 azido-trans-2-butenoate 23 and o 22246 X ~J~ N2N~5 29 methYl 2-(2~S-chloro-3~S-phthalimido-4~-oxo)azetidinyl-3-methyl-4-30 azido-cis-2-butenoate ~ ~8420 l Reaction o~ 2-benzvl-6-(l'-me~hoxvcarbonvl-2'-methvlPro~-2 l'-en,vl)-l-oxa-3,6-diaza-4S, 5R-blcyclo [3,2,0] hept-2-3 en 1 -one wlth one molar equlvalent o~ a lithium thioalkoxide in 4 hexamethvl~hosphoric triamlde (Hvdrolvsis o~ the oxazoline ester to the oxazollne acld and rearran~ement to the ox~en analo~
6 o~ Penlclllln &
7 The equatlon of the above-mentloned reactlon i~
8 ~2Ph 9 ~ 2C ~ . IX2Ph ~ 3 1 o l. RSLi~MPT ~,C~O +

12 ~ ~ ~ H~ H

14 C02C~3 COO~
~5 16 ~ X
= = CH

0~
l9 H COOH

21 Where R = n-C3H7, t-C4Hg 23 HMPT -(CH3~2N-I-N(CH3)2 24 N(~H3~2 .. . . . . . .. . ....

8g20 1 For the varlous experiments described below, EMPT was 2 purifled by dlstillation, under dry nitrogen, from lithium 3 hydride or lithium alumlnum hydrlde at 116-117 C and 4 19-20 torr. It w2s stored over molecular sieves ln a ~laqk fitted wlth a rubber septum, and removed by syringe when 6 needed. The llthlum reagent was generated in HMPT by one of 7 the ~ollowing methods (Method A and Method B~:
8 Method A: A round-bottomed ~lask was equipped with a 9 magneti¢ ~tirrer and rubber septum. Two syrlnges were lnserted lnto the septum, and dry nitrogen wa~ passed 11 through the flask. Then HMPT was introduced and the nitrogen 12 sweep was continued for 1 hr. m e desired amount o~ mercaptan 13 wa~ then added followed, at 25, by an equivalent amount of 14 a solutlon o~ n-butyllithlu~ in hexane. The nitrogen ~weep wa~ oontinued ~or 15 mln. and the ~la~k wa~ then sealed and 16 ~tored in the re~rigerator, aliquot~ of the reagent belng 17 wlthdrawn ~or reactlon as needed. The solutlon was stable 18 ror about one month.
19 Method B: Llthium hydride was placed in a round-bottomed ~la~k equipped with magnetlc stirrer and rubber septum. The 21 ~la~k was ~lu~hed wlth nitrogen and HMRT was then added. The 22 nttrogen ~weep was then continued ~or ~0 mln. before addition 23 ~ the mercaptan. The re~ultlng mixture wa~ stlrred for 1.5 24 hr, at room temperature and wa~ then ~lltered (under nltrogen ln a dry box). ffl e concentration of the reagent was 26 determlned by tltration of an aliquot with N HCl, and the 27 ~lask was then sealed and ~ored ln the re~rigerator until 28 needed.

1 Ex~eriment 1 The o~azollne (200 mg., o.64 mmole~, ln XMPT
2 (1.5 ml.) wa3 treated, under nltrogen and wlth ~agnetlc ~tirring, 3 w$th 1.3 ml. of a 0.58 M ~olutlon (0.75 mmole) of t-BuSLi in 4 HMPT prepared by method A. me addition was per~ormed at room temperature durlng 0.~ hour and the reactlon mixture 6 Wa8 then allowed-to stir overnight. Ice-cold water and ether 7 were then added and the pH was adJusted to 2.~. The ether 8 extract wa8 washed with cold water, dried over anhydrous g magnesium ~ulfate and evaporated to gi~e a yellow oil. m is wa8 dls801ved in ether and the solutlon extracted with ice-11 cold 5% blcarbonate. The bicarbonate extract was brought to 12 pH ~ and extracted with ether. Evaporatlon o~ the dried ether 13 extract gave 120 mg. o~ yellow oil which showed ~-lactam a~sorption 14 1~ the IR at 5-6~u and in the NMR at 4.8-5.0~. This NMR spectrum changed after 7 hours at room temperature.
16 E~erlment 2 The oxazollne t62 mg.J 0.197 mmole), ln HMPT
17 (1 ml.), wa~ swept with nltrogen for 30 mln., and 0.~5 ml.
18 Or a 0.615 M solution o~ t-BuSLi (0.215 mmole), prepared b~ -19 method A, was then added dropwlse d~ring 2 hr. The mixture w~s atlrred for 2 hr a~ter addition was complete and the acldic 21 materlal wa3 then isolated a~ described ln experiment 1. It 22 was a ~ellow oil weighlng 23 mg.
23 Ex~eriment ~ The oxazoline (66 mg., 0.21 mmole),in HMPT (~ ml.), 24 was swept wlth nitrogen, and 0.3 ml. o~ a 0.73 M solutlon of n-C3H7Ll, prepared by method A, wa~ then added dropwlse in two 26 portlon~; 0 2 ml were added durlng 0.5 hr., the mixture was 27 ~tlrred for 1 5 hr., and the remainder was then added during 28 0 5 hr. The reactlon mixture was kept at room temperature ~or 29 8 hr. and then stored overnight in the refri~erator. Isolation ~lelded 24 mg. o~ acidlc material.

z ~ ~ ~
- ) ~8420 1 ~xperlment 4 The oxazollne (64 mg., 0.20 mmole) was dlssolved 2 ln HMPT (1 ml.) and the solutlon was degassed wlth a stream 3 Or dry nltrogen for 45 min. Then 0.44 ml. of a 0.47 M
~olutlon of t-BuSLi (prepared by method B) was added during 35 min. Stlrrlng was continued for 2 hr. and the acldlc 6 materlal wa~ then isolated. It welghed 15 mg.
7 Each Or the acidlc compounds lsolated ~rom experiments 2-4 reatured NMR peaks at 2.52 (phenyl), 3.77 (d,3.5 Hz), 9 4.0 (d,3.5 Hz), 6.18, 7.77 and 8.47. These are the peaks of a com~ound havlng the structure 12 1 2Ph 13 N~ ~
14 ~l~l ~ H
~ _ IJ

COOH
18 whlch could be obtalned ln crgstalllne form by an slternatlve 19 route. Each o~ the NMR spectra of the aclds Prom experlments 2-4 also showed extraneous peaks, the most promlnent being a 21 alnglet at 1~6.~ and a singlet at 8.75, correspondlng to a 22 proton alpha to a carboxyllc aold and methyl groups attached 23 to a quaternary centre.
24 T~he crystalline oxazoline carboxyllc acid was ~ound to be lnactlve as an antibacterlal agent at levels Or 250 mcg./ml.
26 ~owever, all of the acldic fractions prepared by hydrolys~s 27 of the methyl ester showed slgnl~lcant antlbacterial actlvity.
28 The acld ~rom experlment ~ (whlch also contalned the blologlc~
29 actlv~ oxazGllne carboxyllc acld) was d~s~olved ln dlmeth~l-sulfoxide, c~romatographed, and compared with Penlcilllr. G.

--9!~--.

1 The two substances were spotted on duplicate 1/2 lnch strips 2 o~ S and S 589 blue ribbon paper. After overnight development 3 in a ~ystem containlng n-butanol 60:acetlc acid:l5:water 25, 4 the strips were alr drled and one set was ~prayed wlth Rlker penlcillina~e. Both ~et~ were then sub~ected to bioautography 6 on ~. subtllis. The antlbacterial agent in the acid from 7 experiment 3 was found to have an Rf virtually identlcal to 8 that of penicillln G and the bioactivity was eliminated by 9 penlclllinase treatment, as expected for a compound havlng a structure similar to that of penicillin G.
11 MIC data on penlclllln G and on the acid ~rom experiment 12 3 are summarized in the followlng table.

19 .
.21 3~

1 Or~ani~m Penicillin G Control Acid from Ex~eriment MIC mc~./ml.
2 M.I.C. mc~./ml.

4D. pneumonlae .~04 8 ~ 5% serum*
Str. pyogenes 004 8 6~ 5~ serum*
7S. aureu~ Smith .016 16 at 10 ~ dil'n S. aureu~ Smith .06 63 gat 10- dll'n ~ 50~ serum 10S. aureus BX-1633-2 125 63 11at 10-3 dll'n 12 S. aureu~ BX-1633-2 > 125 125 at 10- dll'n S. aureu~ Meth. 125 32 14 Reslst. at 10-3 dll'n S. aureu~ at 10 3 dil'n 63 32 16 S~ aureus at 10-2 dll'n ~ 125 ~125 17 Sal. ~nteritldls at0.13 63 10- dil'n E. ¢oll Juhl at 10-4 32 63 19 ~ n E. coli at 10-4 dll'n125 125 21 K. pneumonlae at 10 4 2 63 dil'n 22 Pr. mirabllis at 10-~ 1 63 23 dil'n 24 Pr. morganli at 10-4> 125 63 dll'n Ps. aerugino3a at 10-4> 125 63 26 dil'n 27 Ser. marcescen~ at 10-4 > 125 63 dll'n * 4 ~ AAB at 10 dll'n 3 50% Medium Shown 1 On the basis o~ it~ antibacter~al spectrum, susceptlbillty 2 to penicllllnase, and NMR ~pectrum the antibacterlal agent 3 prepared during the hydrolysis o~ the oxazollne ester ls assigned the structure 5.
6 . O H X H Me 8 PhCH2 C N ~ ~COOH

oxapenicillin G
11 2,2-dimethyl-3R-carbo~y-6S-phenylaceta~ido-1 oxa-4-aza-~R-12 bicyclo [3,2,0] heptan-7-one.

~9 21 .

~93~

1~18420 1 Reactlon of 2-benzvl-6~ 'methox~carbonYl-2'-methvl~ro~-2 1'-envl)-1-oxa-~.6-dlaza-4S.SR-blcvclo [~ 2.0] he~t-2-en-3 7-one wlth two eaulvalents o~ a lithium thloalkoxlde ln 4 hexamethvlPhos~horlc triamlde.
The oxazoline (74 mg., 0.2~6 mmole) was dissolved ln 6 ~MPTI (1.5 ml.) and the solutlon was degasæed with dry 7 nltrogen for 0.5 hr. Then 0.8~ ml. o~ a 0.612 M solution 8 o~ t-BuSLl (0.508 mmole), prepared by method A, was added 9 during 0.5 hr. and the mixture was stirred overnlght. The a¢idl¢ ~ractlon welghed 33 mg. and showed antibacterlal 11 a¢tlvlty in a plate assag vs. S. ;~ a. The NMR spe¢trum 12 showed ~-la¢tam protons at 4.0 and 4.7 Hz, phenyl absorption 13 at 2.6, methylene absorptlon at 6.12, a singlet at 6.2 and 14 methyl peak~ at 8.75. The characterlstlc peak~ of the o~azolinecarboxylic- acid, 2-benzyl-6-(1'-carboxy-2'-methyl-16 prop-1~-enyl)-1-oxa-3,6-diaza-4S,5R-bicyclo 13,2,0~ hept-2-17 ene-7-one, were absent ~rom the spectrum.
18 m e same re~ult was obtained rrom an experiment wlth 19 t-BuS~l prepared by method B.
. .
~hese experlments demonstrate that hydrolysis of 2-benzyl-21 6~ -methoxycarbonyl-2l-methylprop-1'-engl)-1-oxa-3,6-dlaza-22 4S,5R-blcyclo ~3,2,0~ hept-2-en-7-one to the carboxyllc acid 23 18 e~ected bg lithlum thloalkoxides ln HMPT and that rearrange-24 ment to the oxapenicillin occurs under the experimental conditions.

3o _9~_ , 1 Reaction o~ the e~imeric meth~l 2-(2'-chloro-3'S-amlno-2 4~-oxo~azetidinvl-3-methvl-2-butenoate~ with benzYl chloro-3 formate ~carbobenzox~ chloride~, 4 The crystalline p-toluenesulfonic acid salt of methyl 2-(2~R-chloro-3'S-am~no-4'-oxo)azetidinyl-3-methyl-2-6 butenoate (576 mg., 1.42 mmoles) was dlssolved in spectro-7 ~copic grade chloro~orm (6 ml.), and 1 080 g. (5 molar 8 equivalents) o~ tetramethylguanidinium chlorlde were added.
9 The mixture wa~ re~luxed for 3.5 hr. and then cooled, washed wlth water, dried over anhydrous magnesium ~ulfate, and 11 carbobenzoxy chlorlde (297 mg., 1.7 mmoles) was added followed, 12 dropwise, by a solutlon of triethylamine (185 mg.~ 1.8~ mmoles3 13 in dry chloroform (5 ml.). After 45 min. stirring at room 14 temperature the reaction was topped by addition o~ water.
The organic la~er was drled and evaporated to a residue of 16 353 mg. Thls wa~ chromatographed on silica gel and the column 17 eluted with 1:1 petroleum ether (~o-600) _ ethyl acetate; 17 18 thirty ml. fractions were collected. Fractlons 2-4 gave 19 108 mg. o~ a compound having the structure 3o _95_ 4 PhCH20 - C

6 o 8 The NMR spectrum of this compound has peak~ at 2.67 (5H), 9 4.20 (lH,d,2Hz), 4.87 (2H), 5.35 (lHJdJ2Hz~, 6.27 (3H), 7.73 (3H), 8.o3 (3H).
11 Fractlon3 12-17 afforded 54 mg. of a compound a~signed 12 the structure 13 ll .
14 HN/C ~p H~ lX

Thls fused ~-lactam-oxazolidone has a molecular ion at m/e 240 21 ln lts mas~ spectrum. The IR spectrum has peaks at 3.0, 5.56, 22 5.62, 5.78, 6.10~. The NMR spectrum has peaks at 2.87 (lH,br), 23 3.92 (IH,d,4Hz), 5.o8 (IH,d,4Hz), 6.20 (3H), 7.70 (3H), 8.02 24 (3H).

.s .

- f j 1 Reactlon o~ 2-(2'-chloro-~'S-amino-4'-oxo~azetldin~
2 methYl-2-butenoic acld with carbobenzox~ chloride.

H2N ~ H H Cl ~L~J~ >PhCH20 - C - N;[~
CbOH

11 The p-toluenesul~onic acid salt of anhydro-6-amino-12 penicillin (557 mg., 1.51 mmoles) was chlorinated in methylene 13 chloride at 0 The solvent was then removed under reduced 14 preasure at 20. The residue was disRolved in a mlxture of water (4 ml.) and acetone (5 ml.) and this solutlon was 16 malntalned at 0 for ~ hr. to effect hydrolysis of the acid 17 chloride. Then sodium bicarbonate (705 mg., 8.4 mmoles) was 18 added ~ollowed, dropwise at 0, by a solution of carbobenzoxy 19 ¢hloride (660 mg., 1~51 mmole~) in dry acetone (5 ml.). The reactlon mixture was stlrred for 1 hr. and the product was 21 then lsolated by dllutlon with water, extractlon with ether, 22 drying over anhydrous magnesium sulfate, and e~aporation.
2~ The IR spectrum showed peaks at ~.0, 5.60, 5.62, 5.82-5.88~u.
24 This experiment demonstrates that the amino acid can be acylated succe~sfully.

-97~

1 Chlorination o~ anhYdro-a-~henoxvethyl~enlcillin 2 The anhydropeniclllin (500 mg., an 80: 20 L:D mixture o~ side chaln diastereomer~) was chlorinated at room 4 temperature in methylene chloride uslng a 3tron~ sweep o~
chlorine ~or 15-20 seconds. The ~olvent was then removed 6 at 20. The resultlng product 1~ a mixture of i~omers 7 ha~lng the structure Cl- ~ -0 ~ J

C0~1 It~ NMR spectrum shows peaks at 2.3 ~lH,d,9Hz), 2.75 (2H,d, 16 9Hz), 3.13 (ZH9d,9Hz), 3.92 (IH,m), 4.45 (IH,m), 5.28 (lH,m), 17 7.74 (3H), 7.86 (3H), 8.40 (3H,d,7Hz). The IR spectrum 18 shows peaks at 2.95, 5.55, 5.91~.
19 Ihi~ experlment demonstrates that a 6-acylamino anhydro-penlclllln can be chlorinated successfully.

,0 .

~ J f 1 Hvdrolvsis o~ the anh~dro-a-~henoxyethylpenicillln 2 chlorination ~roduct 3 The above-mentioned trichloro compound was dlssolved 4 ln acetone (5 ml.), the ~olution cooled to 0, and a solutlon Or sodium bicarbonate (284 mg.) in ice-cold water (5 ml.) 6 wa~ added dropwise wlth stirring. Some olly material 7 precipitated during this addition and acetone (15 ~1.) wa 8 there~ore, added when the addltion wa~ complete. The resulting g pale yellow solution was stirred ~or 2 hr. at 0 and then dlluted with cold water (100 ml.). Extraction with methylene 11 chloride, drying over anhydrous magnesium sul~ate, and e~aporatlon 2 afforded a pale yellow oil. This materlal i3 assigned the 13 structure i 11 7 -- ~ `
16 Cl ~ O - C - C - N

18 8 ~ L COOH
19 20~ D

21 The IR spectrum showed peaks at 2.9, 5.58, 5.85,u. The compound 22 was dis~olved in methylene chloride and the solution extracted 23 wlth 5% sodlum bicarbonate. The aqueous extract was re-acidiried 24 to pH 2.5 and re-extracted with methylene chloride. Evaporation Or the dried methylene chloride extract gave materlal, havlng 26 high antlbacterial activity vs. S. lutea, which is a~si~ned 27 the structure _99_ Cl ~ O - C ~ ~H COOH

7 Treatment of this material with diazomethane gave a meth~l 8 ester which showed~ in the IR, a peak at 5.6~ and, in the NMR
9 a peak at 8.75 cons~stent with the presence o~ a ~-lactam and methyl groups attached to an oxazolidine ring.
11 In a ~econd experiment, the chlorination product from ~2 215 mg. (0.62 mmole) of anhydro-~-phenoxyeth~lpenicillin was 13 dis~olved in ice-cold tetrahydrofuran (3 ml.) and to the 14 colorle~s solutlon was added ice-cold water (2 ml.). The re~ulting solution was stlrred at 0 for 2 hr., then diluted 16 wlth ice-cold saturated sodlum ¢hloride and extracted with 17 methylene chloride. Evaporation of the dried ~ethylene 18 chloride e~tract af~orded 277 mg. of a white foam. The NMR
19 spectrum of this dichloro acid shows peak~ at 2.30 (lH, br), 2.72 (2H,d,8Hz), 3.10 (2H,d, 8Hz), 3.83 (lH,br), 4.40 21 (lH,br), 5.22 (lH,q), 7.67 (3H), 7,93 (3H), 8.40 (3H,d).
22 The IR ~pectrum showed peaks at 2.96, 5.60, 5.8 ; ~

_ ~ ~f ~

1:~L18420 1 BQ~tion of 2-~2l-chloro-~ls-amlno-4-oxo)azetldin~ methvl-2 2 butenoic acid with Phen~lacetvl chlorlde.

S ~ ~ PhCN2C~

8 COO~ COOH

9 m e p-tolueneSulfonic acid salt of anhydro-6-amino-peniclllln (242 mg.) was chlorlnated and the product hydrolyzed 11 in aqueous acetone as already de~cribed. To the result~ng 12 801utlon (volume 20 ml.) at 0 was added in portlons sodium 13 bicarbonate t275 mg.) ~ollowed by a solution of phenylacetyl 14 chlorlde (152 mg.) in acetone (5 ml.) in one portion. The mixture was stlrred for 30 mln. and then dlluted with water 16 and extracted wlth methylene chloride, this extract wa~
17 discarded. The aqueou~ pha~e was brought to pH 3 and extracted 18 wlth methylene chloride. Thi~ extract was dried over 19 anhydrous magneslum sulfate and evaporated to glve the desired compound. The IR and NMR spectra were consistent with the 21 as~lgned structure.

",0 ! `
1~11!~L8420 1 Chlorination of anh~drohenzYlpenicillin 2 Anhydropenicillin G (176 mg., 0.56 mmole) wa~ di~olved ln methylene chlorlde (7 ml.) and the solutlon wa3 chlorlnated 4 at room temperature for ~0 sec. with a ~trong sweep of chlorine.
The solvent wa~ then remo~ed immedlately at 20 under reduced 6 pressure to give a pale yellow ~oam. The IR spectrum o~ this 7 ~oam show~ pea~s at 2.92, 5.5, 5.95~u. ~he NMR spectrum shows 8 that the product i~ a 4:1 ml~ture o~ 2-(2-R-chloro-3~-g phenylacetamldo-4~-oxo)azetidinyl-3-methyl-2-butenoyl chloride and its 2'S epimer. The ma~or i~omer ha3 the structure 11 , 13 PhCH2C ~ l 14 ~ N

i6 COcl 17 It~ NMR spectrum ~hows pea~ at 2.71 (5H), 3.07 (lH,d,9Hz), 18 3.g7 (lH,d,4.5 Hz), 4.52 (lH,q,4.5,9Hz), 6.37 (2H), 7.78 (3E), 19 7.92 (3H).
~ me minor i80mer has the 3tructure 21 H H Cl 22 PhCH2C0 ~ `
23 _~/l N ~
24 ~ r \
COCl -26 Its NMR ~pectrum show~ peak~ at 2.71 (5H), 3.07 (lX,d,~Hz), 27 4.12 (lH,d,2Hz), 5.17 (lH,q,2,9 Hz), 6.44 (ZH), 7.78 (6H).

1 H~drolvsis of th~_anh~drobenzvlpenicillin chlorlnat~on 2 Droduct 3 The above-mentioned mixture of dichlor~des (from 176 mg.
4 of anhydropenicilltn) wa3 di~ol~ed ln acetone (6 ml.) and water (4 ml.) wa~ added followed, at 0, by exces~ ~odlum bicarbonate.
6 The ~ixture wa~ stlrred for ~.3 hr. and then diluted with water 7 (50 ml.) and extracted thrice with methy]ene chloride and once 8 with ether. Acldi~ication of the aqueou~ pha~e to pH 2.~, g extraction with methylene chloride and evaporation of the dried methylene chloride extract afforded 36 mg. of an oll whose IR
1 and NMR spectra lndicated it to conslst mainly of unhydrolyzed 12 acld chloride.
13 In a second experiment anhydropenlcillin G (105 mg.) wa~
14 chlorinated and the resulting whlte foam was dissolved in ice-cold tetrahydrofuran ~3 ml.) and cold water (1 ml.) wa~ added.
16 The clear yellow solution was maintained at 0 for 2 hr. and 17 then poured into a mixture of water and ice, and extracted 18 wlth methylene chloride. Evaporation of the dried methylene 19 chloride extract afforded 113 mg. (98~) o~ a chloro acid whose IR and NMR spectra ~howed it to ha~e the structure 22 ~ H Cl 23 PhCH
24 ~ N~
COOH

,0 - 10~-, 1 The IR 8pectrum showed peaks at 3.05, 5.62, 5~90~ 5~95~uo me 2 NMR spectrum showed peaks at 2.72 (5H), ~.10 (IH,d,8 Hz), 3.93 (IH,d 7 4.5 Hz), 4.42 (IH,q,4.5,8Hz), 6.~2 (YH), 7.72 (3H), 8.01 (3H).
4 In a third experlment, the chloro acid ~rom 3~3 mg. of anhydropenlcillln G was treated in ether wlth an exces~ of 6 ethereal dtazomethane. The solutionwa~ ~tirred ~or 2 hr. at 7 room temperature and then evaporated to dryness. The residue 8 was left in the refrigerator overnight and then, ln methylene g chloride, shaken with 5% bicarbonate, dried and evaporated.
The re~idue was chromatographed on sllica gel; elution with 11 1:1 petroleum ether:ethyl acetate a~forded 189 mg. (51%, 12 m,p, 110.5-111) o~ the methyl e~ter having the structure PhCH2C0 17 C02CH~
lB
19 and 40 mg. (12%) of the oxazollne ~2Ph 21 N ~
22 Hlll ~ H

24 0" ~ ~

l ~oth compound3 were identical to those obtained from the -2 p-toluenesulfonic acid salt of methyl 2-(2~R-chloro~ S-3 amlno-4'-oxo)azetidinyl-~-methyl-2-butenoate. m e reaction 4 sequence proves that chlorination proc~eds in the same manner 5. with the phenylaoetamldo and am~no ide chain~.

2~

. -105-,~ ' !
4;20 1 Svnthesis of_2-benzYl-6~ carboxv-2~-methvlpro~ envl)-2 1-oxa-~.6-diaza-4S.~R-bic~clo [3.2.0] heP~-2-en-7-one 4 H H CH2Ph ~ N~C~
6 ,~ N`~l ~ H ~ H
7 . COOH /L N J
' O --~
~ COOH

The chloro acld prepared from 640 mg. of anhydro-11 penlcill~n G was dissolved in 5% blcarbonate solution. Thi~
12 wa~ extracted wlth methylene chloride and then acidi~ied to 13 pH 2. Extraction with methylene chloride and e~aporation o~
14 the dried extract afforded a cry~talline residue. Recry3tal-llzation rrom ethyl acetate gave 320 mg. (53~) o~ the oxazol~ne 16 carboxylic acid, m.p. 119-122 dec. The IR spectrum shows 17 a broad peak at 4~, and a~ well peak~ at 5.64, 5.92, 6.1~UJ
18 con~iBtent with the zwitterionic structure 19 CH2Ph ~3~C~o 21 HN~ /
~""~ lH

2~ 0/~
24 C02~3 The NMR ~pectrum (in D20) ~hows peaks at 2.67 (5H), 3.88 26 (lH,d,3.8Hz~, 4.75 (lH,d,3.8 Hz), 6.25 (2H), 8.o9 (3H), 27 8.69 (3H).
28 Anal. Calcd. for C16H16N204: C, 63.99; H, 5.37; N, 9.33.
29 Found: C, 64.26; H, 4.89; N, 9.54.
3o J
~L18420 1 Pre~aration of anh~drocarbobenzox~eniciliin 2 The p-toluenesulfonic acid salt of anhydro-6-amino-3 peniclllin (2.90 g., 7.84 mmoles) wa~ dls~olved in methylene 4 chloride (20 ml.) and the solution was cooled to 0 and treated ¢oncurrently with pyrldlne (820 mg.) ln methylene chloride 6 (15 ml.), and carbobenzoxy chloride (1.400 g., 8.1 mmoles) in 7 methylene chloride (15 ml.). Addition o~ the two reagents 8 wa~ oomplete in 10 min. and, after an additional 10 min., the 9 mlxture was washed with ice-cold N HCl, lce-cold ~aturated ~odlum chloride, drled and evaporated to give 2.740 g. of a 11 whlte foam. ThlB wa~ cry~talllzed ~rom a mixture o~ ether and 12 petroleum ether to glve 2.33 g. (89.5%) of anhydrocarbo-13 benzoxypenlcillin having the structure E H
16 PhCH20CONH
17 ~, N
lB

~he NMR ~pectrum showed peak3 at 2.65 (5H), 4.17 (lH), 4.45 (lH), 21 4.85 (2H), 7.82 (3H), 7.93 (3H).

.

, ~ ?

1 Pre~aratlon o~ anhvdro-2.2'.2 " -trichloroethoxv~eniclllin 2 The p-toluenesulfonic acid salt of anhydro-6-amino-3 peniclllin (2.~96 g., 6~47 mmoles) was dl3solved in methylene 4 chloride (25 ml.) and the solution was cooled and treated concurrently with pyrldine (o.633 g., 8 mmoles) ln methylene 6 chlorlde (10 ml.) and 2J21,2~'-trlchloroethyl chloroformate 7 (1.437 g., 6.9 mmoles) ln methylene chlorlde (10 ml.). At 8 the end o~ the addltlon t.l.c. examination of the reactlon 9 m~xture revealed a slngle spot (and a spot at the orlgln correspondlng to pyrldlnlum chlorlde). The mixture was 11 stlrred an addltlonal 15 mln. and then wa3hed wlth cold 12 N HCl, drled and e~aporated. The IR and NMR spectra o~ the 13 resulting whlte ~oam were conslstent with the structure Cl 0 H H H

17 Cl - C - CH20- C - N ~ ~/
18 Cl //L___N
lg 2~

27 , .

. -108-.

1 Conversion_of anhvdro-2.2'.2~'-trichloroethox~Penlcillin 2 ~nto benzhvdrYl 2-(2~R-chloro-~S-trlchloroethoxvcarbonvl-3 amino-4~-oxo)azetidinvl-~meth~1-2-butenoate H H o H H Cl 11 CC13CH20CO~ ,~

COCl H H Cl 16 = _ CC13CH20CO~

21 H H Cl ~22 CC13CH20CONH
2~ ~,L--N

C02CHPh2 26 A. The anhydropeniclllin (453 mg., 1.245 mmole) was 27 ¢hlorinated in the usual way to give a white foam. The NMR
28 spectrum of this foam showed peak~ at 3.35 (lH,d,lOHz), 29 3.83 (lH,d,4.0Hz), 4.52 (lH,dg4.0JlOHz), 5.21 (2H), 7.71 -,0 (~H) J 7.81 (3H).

; ' ' .

1 B. Hydroly~i~ wa~ per~ormed at 0 for 2 hr. ln tetra-2 hydrofuran (10 ml.) and water (1 ml.). The resulting acid-3 cry~talllzed from chloroform. It~ NMR spectrum showed ~ peaks at 3.17 (IH,d,8Hz)J 3.82 (lH,d,4Hz), 4.56 (l~,q,4,8Hz), 5.20 (2H), 7.67 (3H), 7.93 (3H).
6 C. -The acld was dissolved in hot benzene (40 ml.) and 7 dlphenyl dlazomethane (363 mg., 1.87 mmoles) was added.
8 The resulting solut~on was refluxed for 40 mln. and then g evaporated to dryne~s. The dark red oll wa~ chromatographed on slllca gel. Elution wlth graded mixtures of petroleum 11 ether and ethyl acetate a~forded 480 mg. (70%) of the 12 benzhydryl e~ter. It~ NMR spectrum showed peaks at 2.68 13 (lOH), 3.06 (lH), 3.51 (lH,d,9Hz), 4.04 (lH,d,4.5Hz), 4.67 14 (lH,q,4.5,9Hz), 5.23 (2H), 7.72 (3H), 7.98 (3H).

~8 3o -110- , .

1~18420 l Equilibration Or the R and S benzhYdr~l 2-(2'-chloro-3'S-2 trlchloroethoxvcarbonvlamino-4'-oxo)azetldinvl-3-meth~l-3 2-butenoate~
4 The benzhydryl e~ter (181 mg., 0.~17 mmole) and tetra-methylguanidinlum chlorlde (240 mg., 5 molar equivalents) 6 were refluxed in chloro~orm (5 ml.) Por 5 hr. The cooled 7 reactlon mlxture was then diluted with methylene chloride, 8 wa8hed wlth saturated sodlum chlorlde solutlon, dried and 9 evaporated. The resulting white foam wa~ ~ound to be a 60:40 mixture o~ the starting material and lts 2'S eplmer, 11 whlch haa the structure 14 ~ H H
CC13CH2C ~ \\~Cl 16 ~ ~ ~

18 C02CHPh2 The NMR spectrum o~ this compound shows peaks at 2.68 (lOH), 21 3.06 (lH), 4.30 (lX,d,2Hz), 4.95 (lH,d,2Hz), 5.27 (2H), 22 7.72 (~H), 7.98 (3H).
2~ In a second experlment, 4.851 g. (8.65 mmoles) of the 24 2~R l~omer and tetramethylguanldlnium chloride (7.9 g., 6-molar-equivalents) were refluxed in spectroscopic grade chloroform 26 (20 ml.) for 4 hr. The product wa~ a 70:30 mlxture of 21S:21R
27 l~omer~, i.e., these condltion~, whlch involve a higher con-28 centratlon of reactants, cause a significant improvement in the 29 proportion of the 2'S i~omer.
3o ., 1 Tetramethvl~uanldlnium formate ' 2 Commerclal 98~ formic acid was di3tllled Prom anhydrous 3 cupric sulfate at 46 and 113 torr. The dlstlllate was re- ;
4 distllled ~rom anhydrous cuprlc sulfate at 41 and 105 torr to give anhydrou3 ~ormic acid.
6 Tetramethylguanidine (22 g., 0.19 mole) was di~olved in 7 anhydrous ether (100 ml.) and to this solution at 0 wa3 added 8 a solutlon o~ arh~drou3 ~ormic acid (7.1 ml., 0.198 mole) ln g anhydrous ether (40 ml.). m e resulting salt crystallized.
It wa3 collected, waæhed with ether, dried in hlgh vacuum 11 and recrystalllzed from chloroform-ether.
12 The salt was extremely hydroscopic and became oily after ls 3 mln. expoæure to atmospherlc moisture. The oily mater~al ?4 gave unsatiæfactory results ln the followlng experiments.
If the formicacid was not made anhydrouæ prior to 16 rormation of the salt, the latter was obtalned as an oil which ga~e un~atis~actory results. The salt haæ the structure 19 MH2e9 ~0-C-H
Me2N-C-NMe2 2~

~9 ~3L18420 1 Reactlon o~ benzhvdrvl 2-(2~-chloro-~S-trichloroethoxv-2 carbonvlamlno-4~-oxo)azetidlnvl-~-methyl-2-butenoate with 3 tetramethvl~uanidinlum formate. Pre~aration of 2-trichloro-4 ethoxv-6-(1'-benzh~drylox~carbon~1-2'-methyl~ro~ -en~l~-1-oxa-~.6-dlaza-4S.~R-bicvclo[3 2.0]he~t-2-en-7-one 6 A 2:1 21S:2'R mixture of benzhydryl esters (953 mg., 7 1.7 mmoles) and tetramethylguanldlnlum ~ormate 4.992 g.
(30.5 mmoles) were refluxed in 3pectroscoplc grade chloroform 9 (12 ml.). The reactlon was complete ln 1.5 hr. and the mixture wa~, there~ore, cooled, washed successl~ely wlth water and 11 saturated 30dium chloride, dried and evaporated. The resldue 12 was chromatographed over 30 g. of sllica gel. Elutlon was 13 per~ormed with 100 ml. each of 90/10, 80/10 and 70/30 petroleum 14 ether-ethyl acetate, wlth ~O ml. fractions belng collected.
Fractlons 2-5 were combined to glve 142 mg. (24~) of a compound 16 havlng the ~tructure Cl 19 N q . H 1~ H
21 ~ N~
22 1 /Ph CO C~
23 2 - Ph 24 The IR spectrum o~ this oxazoline shows peaks at 5.61, 5.76, 5.81, 6.o7 ~
~6 The n.m.r. apectrum nas peaks at 2.68 (lOH), 3.08(s,iH~, 27 ~ 99(1H,d,3.5Hz), 4.86(1H,d,3.5Hz), 5.15(1H,d,12Hz), 5.27 28 (lH,d,12Hz; the methylene protons of the trlchloroethyl group 29 are non-equivalerlt~, 7.73(3H), 8.o6(3H).

3o The mass spectrum shows chlorine multiplets characteristic

31 f the presence of 3 chlor~ne~ including a multiplet at m/e 522, the molecular ion. -113-1~18420 1 Chlorination o~ anh~drocarbobenzox~enicillin 2 The anhydropenlcillln (470 mg., 1.47 mmole~) was 3 chlorinated ln methylene chloride ~or 15 ~econd3. After 4 an additional 30 ~econds the sol~ent wa~ removed to glve 5. a whlte foam which con~isted of a 77:23 ml~ture of dichlorldes, 6 the compound having the 2'R-chloro configuration predomlna~ing.
7 It~ 3tructure i~ -9 1l 7 H H ~ 1 PhCH20 - C -N

12 COCl ~he NMR ~pectrum o~ this compound has peaks at 2.69 (5H), 16 ~,14 (lH,d,9Hz), 3.93 (lH,d,4Hz), 4.75 (IH,q,4,9Hz), ~.83 17 (2H), 7.80 (3H), 7,90 (3H) 18 ~he mlnor isomer has the structure 222 PhC~20 - g -24 COCl 26 qhe NMR ~pectrum o~ thls compound has peak~ at 2.69 (5H), 3.14 27 (lH,d,9Hz), 4.10 (lH,d,2Hz), 4.8~ (2H), 5.17 (lH,d,2Hz) J
28 7.80 (~H).

1 Hvdrolvs~s of the anh~drocarbobenzoxypenicillin chlorination 2 roduct.
3 The dichloride (a 77:23 2tR:2lS mixture from ~70 mg.
4 of the anhydropenicillin) wa~ dlssolved ln cold tetrahydro-furan (10 ml.) and ice-cold water (1 ml.) wa~ added. The 6 mixture was le~t for 3 hr. at 0 and then added to ice-cold 7 saturated sodium chloride solution. Extraction with methylene 8 chlorlde and evaporatlon o~ the dried methylene chloride g extract afforded 535 mg. of the chloro acids. The ma~or isomer ha~ the structure 12 1l l H H
13 PhCH20 - C - N
115 ~ N~""~

COOH

17 The NMR ~pectrum of this compound ha~ pea~ at 2.68 (5H~, 18 ~,63 (lH,d,lOHz), 3.87 (l`HJd,4Hz), 4.55 (lH,d,4,10Hz), 4.83 19 (2H), 7.72 (3H), 7.98 (3H).

2~

.

Reactlon Or 2-f2'R-chloro~ S-benzvloxvcarbon~rlamino-4'-2 oxo)azetidln~ -methvl-2-butenoic a~ d with sodium blc~rbonate.
3 Pre~aration of the oxY~en analo~ o~ a S-e~lanhvdro~enlclllin.
~ The chloro acid ~rom 470 mg. of the anhydropeniclllln, ln acetone (5 ml.), was added to a solutlon of sodium bicarbonate 6 (247 mg., 2.94 mmoles) ln water (10 ml.). After 1 minute 7 crystalllzatlon began. ~he mlxture wa~ stirred for 15 min.
8 and then dlluted ~rith saturated sodium chlorlde ~olution 9 (20 ml~) and extracted twice wlth methy}ene chloride (10 ml.
each) and once wlth ether (10 ml.). me combined organlc 11 extracts were drled over anhydrous magne~ium sulfate and 12 evaporated. The crystalllne resldue weighed 216 mg.
13 Chromatography on slllca gel af~orded 185 mg. of material 14 wh~¢h was recrystalllzed to glve a compound, m.p. 170-172 dec., ~a] 25 -64.5 (c 0.45, CHC13),whlch has the structure 7 Ph ~ 0 - C - N ~ ~

22 Anhydrocarbobenzoxypenlcillin has ~a]25 + 259 (c 1, CXCl~).
23 The 5-epioxaanhydropeniclllln has IR absorption at 2.98, 5.55, 24 5.65, 5.88 and 6.51~. The NMR spectrum ha~ peaks at 2.44 (6H), 4.14 (lH,d,1.8Hz), 4.82 (2H), 4.98 (lH,q,1.8,8Hz), 7.82 (3H), 26 7.88 (3H). The mas~ spectrum shows the molecular lon at 27 ~16.
28 Anal- Calcd- for C16H16N25 C, 60-75; H~ 5-10; N~ 8 86 29 Found: C, 60.67; H, 5.20; N, 8.99.
3o -^
1~8420 1 PreParation o~ 6-~hthallmido oxa~enlclllin 2 Anh~dro-6-phthallmidopenicillin (606 mg.) was chlorinated in methylene chloride wlth a strong~weep of chlorlne for 30 4 seconds and the solvent was then removed immediately. A
70:30 mixture of 21S:2'R 2-~2'chloro-3'S-phthalimido-4'-oxo)-6 azetldlnyl-3-methyl-2-butenoyl chlorides wa~ obtained. Thi~
7 mlxture wa~ hydrolyzed in a mi~ture of tetrahydrofuran (25 ml~) 8 and water (2 ml.) at 0 for 4 hr. The re~ultlng acld was a 9 77:23 mixture. The maJor isomer has the structure 12 ~ ~ N ~ C

COOH

16 It~ NMR 8pectrum has peaks at 2.12 (4H), 3.62 (lH,d,2Hz), 4.38 17 (~H,d,2Hz), 7.84 (3H), 8.11 (3H). The mlnor lsomer, which has 18 the 2~R con~igurationj has already been de~crlbed.
19 The trans a¢id was crystallized from 1:1 ethyl acetate-ligroin, .
m.p. 164-166 dec. (sealed capillary). The crystalline trans acid 21 ln methylene chlorlde, was shaken with 5~ blcarbonate ~or 5 mln.
22 The aqueous phase wa~ then ~eparated, acidified to pH 4.~ - ~.o 23 and extracted wlth methylene chlorlde. It wa3 then acidlfied to p~
24 2.5 and extracted twice wlth methylene chloride and twice with chlcroform. Evaporation of the combined drled organic extracts 26 a~orded 30 mg. o~ materlal which showed antibacterial activlty 27 versus ~ lutea at one-tenth the level of phthallmidopenicillin. The 28 NMR spectrum showed a peak at 8.73 for methyl groups on an 29 oxazolidlne rlng and ~-lactam absorption at 4.6. The active 3o compound ha~ the structure 1~L18420 2 . o 3 ~ H H CH3 7 Pre~aration o~ benzhvdr~l 2-(2'S-chloro-3'S-phthalimido-4'-8 oxo~azetidin~l-3-methvl-2-butenoate.
9 The crystalline trans chloro acid (526 mg., 1.515 ~mole) wa~ dls~olved in boillng ethyl acetate (12 ml.) and the ~olution 11 was then cooled to room temperature and treated with diphenyl-12 dlazomethane (3~0 mg., a 10~ excess) in ethyl acetate ~18 ml.).
13 Evolution of nitrogen commenced immediately and was complete 14 a~ter 10 mln. The mixture was then refluxed for 1 hr. and evaporated to drynes~. The re31due was chromatographed on 16 30 g. o~ ca gel. Elution wlth petroleum ether-ethyl 17 a¢etate (70-30) removed some unreacted diphenyldlazomethane.
18 Continued elution with petroleum ether-ethyl acetate (1:1) 19 af~orded 772 mg. (9~) of the compound having the ~tructure 23 ~ ~ ~ 1 C2cH \
~6 Ph 27 The n.m.r, spectrum shows peaks at 2.23(4H,d), 2.67 28 (lOH,m), 3.00(1H,s), 3.87(1H,d,1.8Hz), 4.47(IH,d,1,8Hz), 29 7,68(3H), 7.90(3H).
3o Reactlon of benzh~drYl 2-(2~S-chloro-3~S-~hthalimldo-2 4'-oxo)azetidinvl-~-methvl-2-butenoate wlth tetramethvl-3 ~anidlnlum formate. ire~aratlon of benzhvdrvl 2-t2'R-4 ~orm~yloxv-3~$-~hthalimldo-4~-oxo)azetidln~1-3-methvl-2-5 butenoate.
6 The benzhydryl ester (150 mg., 0.292 mmole) and tetra-7 methylguanidlnium formate (260 mg., 1.61 mmole3, 5.5 molar 8 equivalents) were refluxed ln chloro~orm (spectroscopic ~rade) 9 for 17 hr. me ~olutlon was washed successlvely wlth water, ~aturated sodlum chloride and water, and dried over anhydrous 11 magne~lum sul~ate. The residue, a~ter removal of the solvent, 12 was chromatographed over 18 g. o~ sillca gel. Elutlon wlth 13 graded mixtures of petroleum ether-ethyl acetate afforded 14 54 mg. of a crystalllne compound havlng the structure IT ~=

C02CH~ph 22 The n.m.r. spectrum of thls compound has peak~ at -0.74(1H), 2~ 2.19(4H,d), 3.02(1H,s), 2.67(10H,m), ~.92 (lH,d,~.8Hz~, 4.59 24 (lH,d,~.8Hz), 7.75(~H), 8.11(~H).

-1~18420 1 Curtlus rearran~ement o~ the anh~drobenz~lPeniclllin 2 chlorination Product.
3 Anhydropeniclllin G (206 mg.) was chlorlnated for 20 sec.
4 at -6 C. in methylene chloride. The ~olution was maintained for 2 min. at this temperature and then evaporated to dryness.
6 The residue, in chloroform (10 ml.), was treated at -6 with 7 tetramethylguanidinium azide (120 mg., 1.2 molar equlvalents) 8 ~n chloroform (5 ml.). The resulting solutlon was maintained 9 for 1 hr. at -6, and its IR spectrum was then determined. It showed peaks at 3.0, 4.67, 5.60, 5.95~u, as expected for the 11 ~ormatlon o~ a compound having the structure 13 Il I H H Cl 14Ph~H2C

17 . N3 19 The acid azide was isolated by extracting the chloro~orm 20 solution with water, sodium chloride solution, drying, and 21 removal o~ the solvent. It was then dissolved in methylene 22 ¢hlorlde (10 ml.), and the solutlon heated to reflux. After 23 15 mln. the IR spectrum showed a new peak at 4.~3~u, about twice 24 as intense as the peak at 4.67~u. After an additional 15 min.
the peak at 4.43,u was now about s~x times as intense as the 26 peak at 4.67,u. After a total of 2 hr. o~ refluxing the reaction 27 seemed complete and the IR spectrum showed peaks at 3.12, 28 4.42, 5.58, 5.98)u lllB420 1 Evaporation gave a compound hav~ng the structure 5, PhCH2CONH~C 1 6 f o'~/~

8 N=C-o 9 This lsocyanate, in tetr~hydroruran (20 ml.), was added during 40 min. to 1:1 àqueous tetrahydrofuran containing o.65 ml~ of 11 N XCl. m e mixture was stlrred for 80 min. a~ter addltlon 12 wa~ complete and was then diluted wi~h water (200 ml.), 13 saturated wlth sodium chloride and extracted exhaustively with 14 methylene chloride. The methylene chloride extract was drled o~er anhydrous magneslum sul~ate and evaporated to give 1~9 mg.
16 o~ a white foam. The NMR spectrum o~ thls foam showed ~-lactam 17 peak8 in the 3,9-4,7Jr region, absence of peaks in the region of 18 the allylic methyl groups and several peaks in the 8.5-91r 19 region. Chromatography on silica gel afforded two compounds.
One, a crystalline material, was identified as isobutyramide 21 ~(CH3)2CHCONH2]; the other was a 2:1 mixture of epimers having 22 the structure 23 H H Cl 24 PhCH2C0 ~ CH~

226 ~ ~f\CH

3o ~ 2 1 m e cis isomer, having the structure PhCH2CONH ~ l 6 ~ 0/
7 0 CH~

9 has NMR peaks at 2.63 (5H), 3.5 (lH,d,8Hz), 3.94 (lH,d,5Hz), 4.32 (lH,q,8Hz), 6.28 (2H), 6.83 (lH,m), 8.75 (6H,m).
11 The tran8 isomer, having the structure - H ~ ~Cl PhCH2CONH ~ j~\\ CH3 17 0~ ~ ~ CH3 19 has NMR peaks at 2.63 (5H), 3.5 (lH,d,8Hz), 4.07 (lH,d~2Hz), 5.48 (lH,q,2,8Hz), 6.33 (2H), 6,83 (lH,m), 8.75 (6H,m), 21 The ma88 8pectrum of the mixture of lsomers shows an 22 M-l peak at 306 and 308 and a peak at 272 corresponding 23 ~o loss o~ chlorine from the molecular ion.

3o ~ 20 l A~ dl~closed above, the present inventlon include~ a 2 variety of.proce.~se~ incIud~ng those de3cribed in detail below.
3 To avoid unnece~ ary-repetitlon, lt is to be noted that in the 4 equations glven below there 1~ frequent rererence to the ~ubstituent haYing the formula 7 . R - N - -9 whère~n frequentl~ R~ i~ hydrogen and Rl i8 acyl. By acyl is mean~t a group having the formula 11 " ' ' . , - ' .
12 ll 1~ Ar - CHC -; Ar - X - C - C -; Ar - C -; .
14 : .R4 ~6 ~ oR7 ~ O Ar 17 ~c~ c-;

O
21 . O C - R

22 ~ R9 ~ C//;

26 ' O
27 X ~ C - OH
28 Ar - NH - C -; ~ C -29 . O

~0 - . ~

2 zl 0 X
3 z2 _ C - C -; R~ R12 _ 0 6 wherein R12 repre~ents 2,2,2-triohloroethyl or benzyl;

7 wherein R4 represents hydrogen, amino, carbobenzoxyamino, 8 phenyl, fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy 9 or (lower)alkoxy; X represents oxygen or sulfur; R5 and R each represent hydrogen, phenyl, benzyl, phenethyl or (lower)alkyl;
11 R7 represents (lower)alkyl; R8 and R9 each represent (lower)-12 alkyl, (lower)alkylthio, benzylthio, cyclohexyl, cyclopentyl, 13 cycloheptyl, benzyl, phenethyl, phenylpropyl, furyl, thienyl, 14 naphthyl or Ar; R10 represents (lower)alXylam~no, di(lower)-alkylamino, cycloalkylamino having 3 to 7 carbon atoms inclusive, 16 allylaminoJ diallylamino, phenyl(lower)alkylamino, morpholino, 17 lower(alkyl)morpholino, di(lower)alkylmorpholino, morpholino-1~ (lower)alkylamino, pyrrolidino, (lower)alkylpyrrolidino, di-19 (lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino, di(lower)alkylpiperidino, 1,2,5,6-21 tetrahydropyridino, N-(lower)alkylpiperazino, N-phenylp$perazino, 22 N-(lower)alkyl(lower)alkylpiperazino, N-(lower)alkyl-di-(lower)-23 alkylpiperazino, furfurylamino, tetrahydro~urfurylamino, N-(lower)-24 alkyl-N-fur~urylamino, N-alkyl-N-anilino or (lower)alkoxyanllino;
zl, z2 and Z~ each represent (lower)alkyl or Ar-; Rll represents 26 (lower)alkyl, (lower)cycloalkyl, naphthyl, benzyl, phenethyl or 28 Ar - C -29 and Ar represents a monovalent radical having the formula .~

R2 ~ ~ or - R .
6 whereln Rl, R2 and R3 are each hydrogen, chloro, bromo, lodo, 7 trlfluoromethyl, phenyl, (lower)alkyl or (lower)alkoxy, but only 8 one of said Rl, R2 and R3 groups may represent phenyl; and 9 partlcularly hydrogen, hydrogen tosylate, phenylacetyl, phenoxy-aaetyl, carbobenzoxy, trichloroethoxycarbonyl, a-aminophenyl-11 a¢etyl, a-car60benzyloxyaminophenylacetyl and, when Rl and R2 12 are taken ln comblnatlon wlth the nitrogen atom to which they 13 are attached, phthalimido. The same structure~ are also represented 14 ln some of the equations below as the acyl group Rl - C ~
In some of the equations below esters of the carboxyl group 16 are represented as -- C~ - OR; in such cases R is (lower~alkyl, and 17 pre~erably methyl or t-butoxy, trichloroethyl, benzhydryl or 18 benzgl.
19 Wlth the abo~e deflnitions in mlnd the preferred processes o~ the prP~ent lnvention are summarized as follows:
A, The proce~s for produclng a compound of the ~ormula 21 R Cl 22R - N - ICH . CIH ~ C(CH~)2 23~ C N - C \ o 24O C - Cl wherein R i3 hydrogen or acyl and R is hydrogen or, in 26 combination with Rl and the nitrogen atom to which they are 27 attached, phthalimido which comprises chlorlnating, ~pre~erably 28 whereln the chlorinating agent is chlorine, sulfuryl chlorlde or 29 a complex of chlorine and pyridine hydrochloride], a compound of the formula , 3~1~ 8 2 R~ CH CH \C = O
3 ~ C - N C - C(CH3)2 wherein Rl and R2 have the meanlng set out above;
6 B. The proce~s of producing a compound o~ the ~ormula 7 .R Cl 8 Rl - N - CH CH
9 ~C--I C - ~(CX~)2 o o l~o 11 ' C - OR
12 wherein Rl i9 hgdrogen or acyl; R2 is hydrogen or, in combination 13 with Rl and the nitrogen atom to which they are attached~
14 phthalimido; and R iR (lower)alkyl, trichloroethyl, benzhydryl or benzyl which compriseR mi,xing with an alcohol having the ~ormula 16 ROH a compound o~ the formula 181 Rl Cl ~C N - C _ C(CH3)2 21 0 C ~ - Cl 22 .
2~ wherein R, Rl and R have the meaning ~et out above~
24, ~ 2V

2 C . The proces~ of produclng a compound of the formula 3 l I Cl .
4 . R - N - CK 5~
~ C ~ N - Cl _ C(CH~)2 wherein Rl ls hydrogen or ac~l and R2 i~ hydrogen or, in combination with Rl and the nitrogen atom to which they are attached, phthalimldo 11 which comprises mixing with water 13 a compound o~ the ~ormula R2 ll 16 * - N - CH - C~
17 . ~ C N - C _ C(C~3)2 18 ................... ~~
19 whexeln R~ and R2 ha~e the meaning set out above~

3o ~18420 D. The process o~ producing a compound o~ the formula 2 ~1 3 ~ C \
4 N\ /
~E-CH
// -N - C - C(CH3)2 I O I ~ - OR

g wherein Rl is benzyl or phenoxyme hyl and R is (lower)alkyl (and pre~erahly methyl or t-butyl), trichloroethylJ
11 benzhydryl or benzyl 12 .
13 .which comprises mixing with alumlna or silica gel 14 . - .
a compound o~ the formula 16 . O Cl 17 Rl - C - NH - CH - CH
18 , ~C N.- C - C(G~3)2 19 . , ' O l,o C ~ - OR

21 whereln R and Rl have the meanlng set out above~

1 E. ~he proceaa o~ producing a compound of the formula 4R~ - N - CH - CH
61 - N - a - C(CX3)2 7 . . -wberein Rl la hydrogen or acyl; R2 is h~drogen or, in ¢ombinatlon with Rl and the nitrogen atom to wbich they are attached, phthalimido; and R ia (lower)alk~l (and preferably 11 methyl or t-butyl), trichloroe~h~l, benzh~dryl or benzy~

l3 which comprises reacting wlth azide ion 14 .
a compound of the ~ormula 17 R2 Cl . .~.
18 Rl - N - C~

20DC ----N - I ~ C(C~3~2 21whereln R, Rl and R2 have the meanin~ set out above;

Z~

l F. The process of produclng a compound o~ the formula R - N - CH CH. / CH ~ r 6 ~ C~ = C \
o l~o ~3 wherein Rl 1~ hydrogen or acyi; R2 is hydrogen or, in 11 ao~bination wlth Rl and the nitrogen atom to which they are 12 attached, phthalimido; and R is (lower)alkyl ~and preferably 13 methyl or t-butyl), trichloroethyl, benzhydryl or benzyl whi¢h comprlses reacting wlth about one mole o~ an allyllc 16 brominatlng agent (and preferably wherein the allylic brominatlng 17 agent is N-bromosuccinimide and a catalytlc amount of an orgsnic 18 peroxide 1~ pre~ent).

a compound of the ~ormula 22 ~2 C~
23 Rl _ N - CH I .
24 / C - N - C = C(CH3)2 . O C~ - OR

28 whereln R, Rl and R2 have the meanlng set out above;

--1~0--G. The process o~ producing a compound of the formula 3 R2 Cl C - N - C - C
6 ! ~ I O ~ CH3 7 . . C - OR

wherein Rl i8 hydrogen or acyl; R~ is hydrogen or, in 9 combinatio~ with Rl and the n~trogen atom to which they are attached, phthalimido; and R is (lower)alkyl (and preferably ll methyl or t-butyl), trichloroethyl, benzhydryl or benzyl 13 which comprises reacting wlth about one mole o~ azide ion 14 (and preferably wherein the source of azide ion i8 tetra-methylguanidinium azide).

17 .a compound o~ the ~ormula 19 -- . .
20Rl2 Cl 21Rl - N - C~ - CH~C~Br 22 . I ~ - OR

wherein R, Rl and R2 ha~e the meaning set out above; .

~0 -1~1-H. ~he process of producing a compound o~ the ~ormula R2 Cl 3 1 1 1 .
4 R - ~ - CH CH . CH2 2 C - N - C - ~
1- ~
6 , C - OR

8 wherein Rl ls hydrogen or acyl; R2 is hydrogen or, in g ¢ombinatlon with Rl and the nitrogen atom to which they are attached, phthallmido; and R i8 (lower)alkyl, trichloroethyl, 11 benzhydryl or benzyl 13 which comprises hydrogenating (preferably in the presence o~ a 14 platlnum oxide cata~yst a compound of the foFmula 17 R2 ~1 18 Rl - N - CH C~ ~CH2N3 0 1 ~ OR

22 wherein R, Rl and R2 have the meaning set out a~ove;

3o -1~2-I. The prooess o~ produoing a compound of the formula Rl _ C - N~ - C~ CH C~ ~ C~

~C N ~HCOOH
6 , I O

wherein Rl i3 benzyl or phenoxymethyl which comprlses reactlng with about one mole o~ a compound o~
Il the formula R2SLi whereln R2 is (lower)alkyl (and pre~erably 12 n-propyl or t-butyl), in solution in the compound havlng the ' '~ormula 16 ( ~ ) N - ~'- N(C~3)2 1~, . .
a compound of the ~or,mula ,c 19 N~' /
CH - CH
21 ~ C - N - C _ C(CH3)2 22 , ' O l O
. C - OR

26 wherein ~1 ls benzyl or phenoxymethyl and R is (lower)alkyl 27 (and pre~erably methyl or t-butyl), trlchloroethyl, benzhydryl 28 or benzyl~

3~ .

1 J. m e process of producing the compound o~ the formula 4 ~ ~ - fH IH f - CH~ .
~C - N - CHCOOH

7 which comprises reacting with a deacylat~ng agent .9 a compound o~ the formula 11 Rl _ C - N~ - C~--C / \ C / 3 14 ~ C - N - CHC~OH
~ .
16 wherein Rl 18 benzyl or phenoxymethyl and the deacylatlng agent 17 i8 preferably S. la~endulae or E. coli or whereln the 18 dea¢ylation process is conducted by successi~e addition of 19 trlmethylchlorosilane, pho~phorus pentachloride and methanol;

2~ .

3o . -134-1 K. The process o~ produsing a compound of the ~ormula 3 . / O \

. ~ C N- COOH
6 ! o 7 wherein Rl - C - . is acyl which comprises acylating the 8 compound o~ the ~ormula 11 ~ O

C N. CHCOOH
14 0~ ' ' . . , 16 ~lth a carboxylic acid of the ~o~mula Rl - COOH or lts 17 equivalent,as an acy,lating agent ~or a primary amino group, 18 and espe¢lally sald proces~ ln whlch the acylating agent is l9 the correspondlng carboxylic a¢ld chloride, acid bromide, and anhydrlde, acld mi~ed anhydrlde with a (lower)alkyl ester o~
21 carbonlc acid or free acid ln combination with a carbodlimide7 24 ,.~;-~8 -1~5-~ - - -~4~

1 In another preferred embodiment of sald proces~ the 2 acyl group 1 8 i8 1~

6 1 ~ NHB_ g wherein B i8 an easily removable blocklng group and especially ls selected ~rom the group consisting of hydrochloric acid, 11 carbobenzyloxy, aliphatic ~-diketones and aliphatic ~-diketo esters, 12 e,g. hydrogen chloride or methyl acetoacetate;

1 L. ~he proces~ o~ producing a compound of the ~ormula 4 Rl - C - NX - C~ - C~ ~ 2 ~ C --- N \ ~C:- CH~
o f . COOH

whereln Rl - C - i8 acyl which comprises acylating the compound o~ the ~ormula 11 , 12 / N \
13 H2N - CH _ CH I 2 16 . COO~ .

wlth a carboxylic acid o~ the ~ormula Rl - COOH or its e~uivalent 18 as an acylatlng agcnt ~or a primary amino group, and especlally said process in which the acylating agent is 21 the corresponding carboxylic acid chloride, acid bromide, acld 22 anhydrlde, acid mixed anhydrlde with a (lower)alkyl ester o~
23 carbonic acld or free acid ln combination wlth a carbodiimide~

so -1~7-,, .

~x~ l i~ ~

1 In another preferred embodlment of said process the 2 acyl group1 R is ~ . R - C - ~

~ ~

7 ! NHB
g wherein B is an easily removable blocklng group and especially o s selected ~rom ~he group consisting of hydrochloric acid, 11 carbobenzyloxy, aliphatlc ~-diketones and aliphatic ~-dil~eto esters, 12 e.g. hydrogen chloride or methyl acetoacetate;

16 ' 23 .

. . ,i 27 .

ol38- 1 .

3 ~18420 M. The process o~ produclng the compound of the formula 3 / N~ :
7 l ciH2 o~i \ ~ ~ .

7 COO~

which comprises reacting with a deacglating agent a compound o~ the formula ll . -H

12 R~ NH - C~ CH IC~2 14 . O C

18 wherein Rl 18 benz~l or phenoxymethyl and the deacylatin~ agent 19 i8 pre~erably S. lavendulae or E. coli or the deacylation proces~
20 i8 conducted by succe~si~Je addition of trimethylchloros~lane, 21 pho~phoru5 penta¢hloride and methanol; and 3o -1~9--- -- --~:118~

2 N. m e process o~ producing a compound of the formula 1 1 / N \
.sl .1 f~2 5 ~/CN \ // CH3 8 wherein Rl is hydrogen or acyl and R2 is h~drogen or, in 9 ¢ombination wlth Rl and the n~trogen atom to which they are .
attached, phthalimido whl¢h comprlses saponi~ying, preferably w~th potassium t-.
3 butoxide a compound of the ~ormula -16 R2 Cl.
17Rl _ ~ - CH _ CH

oj/ ~ ~ CH2NR2 I ~ O CH3 C ~ - OR

22 whereln Rl and R2 have the meaning set out above and R is (lower)-' alkyl, trichloroethyl, benzhydryl or benz~

2g - - lil1~34~i~

- 1. The ~-chloroazetidlne-2-ones o~ the present lnvention 2 are useful startlng materials ~or the preparation o~ the class 3 of compound~ called secopenicillln~ and de crlbed in detail in 4Belgium 754,125 (Farmdoc 10051S); they are converted to seco-penicilllns by reaction with sul~ur-co~taining aompounds such 6 as hydrogen sul~ide, 30dium hydrosul~lde, methyl mercaptan 7 . and benzylmer~aptan or salts thereof (represented below a~ R ~ .
8Appropriate compound3 of the present in~ention are 9 ¢onYerted to known cephalosporin~ a~ follows: .
R ~ H
11 Rl ~ Cl whe~ein Rl, R2 and R ha~e the 12 L~ / ~ meanings dlsclosed above and X
~/ / C = C~ ~ Cl, Br, OAc, OCH2~, N3 1~ COOR C.H2Y. NH2, ' OH, -SCN, -SeCN, SeH or -~(OCX2Ph)2 and Y ls X
~3 ~3 or the ~ame as X~
16 , N~2SH
17 . Me2N-- C - NMe2 18 C~2C12 19 ~ / R.T.

22 Rl _ N ~ ~Cl 2234 // ~C = C~

27 base 28 e.g. tertlary aminesJ NaH, potassium t-butoxlde or a 29 . sodium alcoholate \ /

) 2 R2 h 4 ~ ~ ~ oa2Y
COOR

7 . In two prererred embodiments X is.Br and Y is H or Br.
8 There are thus provlded alternatlve routes ~ro~ penicillin3 g produced by direct ~ermentation, ~uch as penicillin~ G and V, bcth ~o other penicillin3 and member3 of the cephalosporin 1~ ~amil~. A8 an example o~ the latter, where Y above 1~
12 bromlne, re~ction with potassium 5-methyl~ ,4-thladiazol-2-15 glthiolate ~ollowed by conversion o~ Rl, R2 and R to h~drogen 14 (ir they are not such already) provides the properly 3-th~o-. 15 lated 7-ADCA nucleu~ whloh i~ then ac~lated in the u~ual manner 16 with l-tetrazol~lacetlc acid to produce cephazolin. ~ another 17 e~ample of the latter, when Y is hydrogen the product contains 18 the nucleu~ 7-ADCA (7-aminode~acetoxycephalo~poraOic acid). .
hu8 when R2 18 hydrogen and Rl i3 Cl~C - CH20 - C - - _ treatment with zinc and acetic acid produce~ an ester o~ 7-AjCA
21 which ¢an be cleaved in the usual manner to give 7-ADCA itself.
22 A8 another example, cephalexin lt~elf i~ produced by the 2~ same sequence o~ reaction~ in which ~ ~ Br, Y i~ H and Rl and 24 R2 taken together wlth the nitrogen atom repre~ent the group 26 C6H5 - CH - C ~
27 ¦ / N-ON - N C.
. / \

342(~ `
, ' ' 1 The anhydropeniclllln u~ed in that case as the origlnal 2 startlng mater~al i~ prepared either by treating N-nitro~o-hetac~llin (prepared ac.cording to Belgium 765,596, Farmdoc 4 67,311S) in the usual manner ror con~ertlng a p~nlcillin to-an anhydro-penlcillin or by coupling D-(-)o2-phenylglycine 6 (a~ with a carbodiimlde) with the compound o~ U,S. pate~t 7 ~,311,638 having the structure _~,S .~o ,, 0~/,, ~ . .

12 ' 13 ~ollowed by rormatlon o~ lt~.acetone adduct and then 14 nitro~ation according to Belgium 765,596, Farmdoc 67,51iS.
' 19 . _ 3L~ 2~
Appropriate compounds of the present invention are used to prepare previously known compounds in the penicillin series, including penicillins themselves, as illustrated by the following reactions:

R ~ H R2 R - N ~ Cl Rl _ N ~ ~\\ Cl o ~ R3 O R

/1. NaSH \
(crown ether) (cryptates) or 2. tetramethyl guanidinium hydrosulfide~
\ ~ \ ~

R ~\SH wherein R i / ; \ CH

in which R4 is hydrogen, (lower)alkyl, trichloroethyl, benzhydryl or benzyl, Rl - N ~ SH

conversion to a penicillin per Wolfe et al, J. Amer. Chem.
Soc. 91, 7205 (1969), when -R3 = \C = C, when R = H aRsDpeGr.
C/OOH3 and Rl = acyl, Cooper and that is, R5-CooH Soc.; 92, 2 1 2575 (1970) R = H and R = acyl ~L18420 Rl -- l~N S--~ cH33 N~C\S

H~COOH H~ H

\R3 Cryptates have been described by B. Dietrich, J. M.
Lehn and J. R. Saurage, J. Chem. Soc (D), 1055 (1970) and crown ether by C. J. Pedersen, J. Am. Chem. Soc., 89, 7017 (1967) and 92, 386, 391 (1970). Both cryptates and crown ether are agents which permit inorganic salts to be dissolved in organic solvents by complexation.

~ - 144a -,. ~ --( ~ 420 . `' `, . .

.

.

lAnother procedure produces secopenlcilllns as follo~s:

2R2 ~ Cl Rl ~

4~ ~ R3 ~ 3 7 ~ ~ R

Rl - N ~ ~' SR
11 ~ ~ R3 N

1~ ' . .
14 When R6 18 benzyl it ls--converted to hydrogen by catalytlc -15 hydrogenatlon to ~urnlsh another route to the sul~hydryl 16 compoun~s above. ~ ~ / C~!
17 In the above equatlons -R3 18 pre~erably - C - ~

19 and Rl, R , R3 a~d R have the meaning used pre-.lously herein.
In the treatment of bacterlal infectlon~ ln man, the 21 new, bicg¢lic ~-la¢tam antlblotlcs of thls inventlon, e.g. the 22 oxapenl¢tlllns ana the azacephalosporins are adminlstered orally 23 or parenterally, ln accordance wlth conventional procedure~ for 24 antlblotlc admlnlstratlon, in an amount of ~r about 5 to 200 25 mg Jkg./day and pre~erabl~ about 5 to 20mg.~kg./da~ in dlvided 26 dosage, e.g., three to ~our times a day. They are administered 27 in do~age unlts contalnlng, rOr e~ample, 125 or 250 or 500 mg. of 2~ actlve ingredient with sultable physiologlcally acceptable carriers 29 or exc~p~ents. ~he do~age un~ts are in the form of llquid pre~aratlons such as solutlon~ ~ suspenslon~ or as ~olid~ in 1 - tablets or capsules.
2 The sub~tltuted azetldlne-2-one3 o~ the present invention 3 are not active as antlbacterial agent~ but do ~unctlon as 4 inhib~tors of the enzyme ~-lactamase and thus decrease the rate of destructlon of a peniclllln when used in combination therewith.
6 Thl ls demonstrated, for example, by reduction o~ the Mlnimum 7 Inhibitory Concentratlon of amplcillln ver~u~ "resistant" or ~-8 lactama~e produclng bacteria such a~ P mor~anli and Ps.
9 ~ from values ln the range o~ 500-lOOO mcg./ml. to values as low a~ 125 mcg./ml. u~ing concentratlon~ o~ the ~
11 substituted azetldlne-2-one ln the range o~ about 125 mcg./ml.
12 ~hese partlcular figures were oOtalned uslng the compound havlng 13 the gtructure .
-15 . ~: : CH
16 , 1 ;
U ~ N
18 ~
19 0/~ N~C = C
I OOH CII~5 , 2~5 27 ' -14~-

Claims (4)

Div. III (C) The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The process of producing a compound of the formula wherein R1 is hydrogen or acyl and R2 is hydrogen or, in combination with R1 and the nitrogen atom to which they are attached, phthalimido which comprises saponifying a compound of the formula wherein R1 and R2 have the meaning set out above and R is (lower)-alkyl, trichloroethyl, benzhydryl or benzyl.

Div. III (C) 2. The process of claim 1 wherein R2 is hydrogen and R1 is ; ; ; ;
; ;
; ;
; or ;

wherein R12 represents 2,2,2-trichloroethyl or benzyl;

Div. III (C)

Claim 2 contd wherein R4 represents hydrogen, amino, carbobenzoxyamino, phenyl, fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy or (lower)alkoxy; X represents oxygen or sulrur; R5 and R6 each represent hydrogen, phenyl, benzyl, phenethyl or (lower)alkyl;
R7 represents (lower)alkyl; R8 and R9 each repreaent (lower)-alkyl, (lower)alkylthio, benzylthio, cyclohexyl, cyclopentyl, cycloheptyl, benzyl, phenethyl, phenylpropyl, furyl, thienyl, naphthyl or Ar; R10 represents (lower)alkylamino, di(lower)-alkylamino, cycloalkylamino having 3 to 7 carbon atoms inclusive, allylamlno, diallylamIno, phenyl(lower)alkylamino, morpholino-lower(alkyl)morpholino, di(lower)alkylmorpholino, morpholino-(lower)alkylamino, pyrrolidino, (lower)alkylpyrrolidino, di-(lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino, di(lower)alkylpiperidino, 1,2,5,6-tetrahydropyridino, N-(lower)alkylpiperazino, N-phenylpiperazino, N-(lower)alkyl(lower)alkylpiperazino, N-(lower)alkyl-di-(lower)-alkylpiperazino, furfurylamino, tetrahydrofurfurylamino, N-(lower)-alkyl-N-furfurylamino, N-alkyl-N-anilino or (lower)alkoxyanilino;
Z1, Z2 and Z3 each represent (lower)alkyl or Ar-; R11 represents (lower)alkyl, (lower)cycloalkyl, naphthyl, benzyl, phenethyl or and Ar represents a monovalent radical having the formula , or Div. III (C) wherein R1, R2 and R3 are each hydrogen, chloro, bromo, iodo, trifluoromethyl, phenyl, (lower) alkyl or (lower) alkoxy, but only one of said R1, R2 and R3 groups may represent phenyl.

3. A compound of the formula wherein R1 is hydrogen or acyl and R2 is hydrogen or in combination with R1 and the nitrogen atom to which they are attached, phthalimido, whenever produced by the process of claim 1.

4. A compound as in claim 3 wherein R2 is hydrogen and R1 is ; ; ;
; ;

Div. III (C) ; ;
; ;
; or or wherein R12 represents 2,2,2-trichloroethyl or benzyl;
wherein R4 represents hydrogen, amino, carbobenzoxyamino, phenyl, fluoro, chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy or (lower)alkoxy; X represents oxygen or sulfur, R5 and R6 each represent hydrogen, phenyl, benzyl, phenethyl or (lower)alkyl;
R7 represents (lower)alkyl; R8 and R9 each represent (lower)-alkyl, (lower)alkylthio, benzylthio, cyclohexyl, cyclopentyl, cycloheptyl, benzyl, phenethyl, phenylpropyl, furyl, thienyl, naphthyl or Ar; R10 represents (lower)alkylamino, di(lower)-alkylamino, cycloalkylamino having 3 to 7 carbon atoms inclusive, allylamino, diallylamino, phenyl(lower)alkylamino, morpholino, lower(alkyl)morpholino, di(lower)alkylmorpholino, morpholino-(lower)alkylamino, pyrrolidino, (lower)alkylpyrrolidino, di-(lower)alkylpyrrolidino, N,N-hexamethyleneimino, piperidino, (lower)alkylpiperidino/ di(lower)alkylpiperidino, 1,2,5,6-tetrahydropyridino, N-(lower)alkylpiperazino, N-phenylpiperazino, SY-l 325 DiV. III (C) N-(lower)alkyl(lower)alkylpiperazino, N-(lower)alkyl-di-(lower)-alkylpiperazino, furfurylamino, tetrahydrofurfurylamino, N-(lower)-alkyl-N-furfurylamino, N-alkyl-N-anilino or (lower)alkoxyanilino;
Z1, Z2 and Z3 each represent (lower)alkyl or Ar-; R11 represents (lower)alkyl, (lower)cycloalkyl, naphthyl, benzyl, phenethyl or ana Ar represents a monovalent radical having the formula , or wherein R1, R2 and R3 are each hydrogen, chloro, bromo, iodo, trifluoromethyl, phenyl, (lower)alkyl or (lower)alkoxy, but only one of said R1, R2 and R3 groups may represent phenyl, whenever prepared or produced by the process of claim 2 or by an obvious chemical equivalent thereof.