DE2349909A1 - 6-Des-methyl-6-des-oxy tetracycline antibiotics - prepd from azlactone and acetone-dicarboxylic ester-mono-amide - Google Patents

Abstract

Cpds of formula (I) and their physiologically acceptable salts are new: (where R1 is 1-4 C (pref. 1-2) C alkyl; R2 is halogen (pref. Cl) or H), and their physiologically acceptable salts are antibiotics with high activity against Gram positive and -negative bacteria, even strains which are normally resistant (e.g. minimum restraining concn. against S. aresis 285 is 0.31gamma/ml for (i; R1 = Me; R2 = Cl) HBr, c.f. 125. 0gamma/ml for tetracycline hydrochloride). They also have higher stability, e.g. in liq. prepns. They may be used orally or parenterally as 2-20 (pref. 3-10) mg/kg unit doses.

Description

UOECi] S? ΛΟ- vo-rßiaJLs master Lucius & Brüninß

/ ilcfcon-z-cichen:

HOE 73 / F 309

Datura: September 26, 1973 Dr »· Ka / stl 6 "desniethyl-6-des-oxytetracycline derivatives

The invention relates to new ones substituted in the 2- and iJ-positions ö-Desmethyl-ö-deoxytetracycline of the formula I

COMHR

(I)

HO

in the

R ^x alkyl with 1 to iJ carbon atoms, preferably methyl and ethyl, and

R is halogen, preferably chlorine, and hydrogen, and their salts with physiologically acceptable acids.

509816/1211 BATH ORIGINAL ¹

Possible substituents R are methyl, /tth.vl, n-propvj. i-propyl, η-butyl, i-butyl and sec. Butyl, preferably methyl and Ethyl...

The invention also relates to a method of production of the compounds of the formula I according to the invention, which is characterized is that you have an azlactone of the formula II in the

2 3

R is halogen, preferably chlorine, and in which R is hydrogen, an alkyl or acyl radical with 1 to 5 carbon atoms, an aroyl radical, a tetrahydropyranyl, benzyl or carbobenzoxy radical, in the presence of strongly basic condensation agents with acetone dicarboxylic acid ester monoamides of the formula III, in which R denotes above
Has meaning, converts to compounds of the formula IV,

"COMIiR-

II

III

NHCOC ^ H, -b 5

CONHR '

CONTHR-

IV

this hydroxylated with oxygen to V, by hydrolysis or
Hydrogenolysis of the BenzoyIschutzgruppe and the protective group R- the tetracyclines of the formula I is obtained, in the case of an introduction

. of R = hydrogen, the intermediate stage V before the cleavage of the

Protecting groups is dehalogenated by hydrogenolysis.

509816/1211
BAD ORfGiNAL

Υ'ύ.ν R ^J are - if the remainder is alkyl or acyl - named for example methyl, ethyl, ii-propyl, i-propyl, n-butyl, i-butyl, pentyl, preferably methyl, as well as formyl, acetyl, Propionyl, butyryl, valeryl, benzoyl, naphthoyl, preferably formyl, acetyl and benzoyl.

The condensed azlactones of the formula II are obtained after a by H. Muxfeldt et al. in J. Am. Chem. Soc. J37 (1965), page 933 described procedure.

The N-s.ubstituierten Acetoridicarbonsäureestermonoamide III receives by, for example, acetone dicarboxylic acid dimethyl ester in a polar solvent at temperatures between -70 and 30 C with monomethylamine to the enamine of Acetondicarbonsäuremonomethy1-ester-N-methyl half amide converts that by concentrated mineral acids in an organic solvent at room temperature for Acetondicarboxylic acid monomethyl ester-N-methyl half-amide hydrolyzed will. - '

In an analogous manner, dialkyl acetone dicarboxylate is obtained with MonoaHey! Amines the corresponding acetone dicarboxylic acid monoalkyl ester-K-ethyl-, -N-propyl- or -N-butyl half-amides.

The üinsetztmc of the compounds II and III is carried out in an inert solvent in the presence of a strongly basic condensate! Onsmittel at reaction temperatures, which depend on the choice of solvent and between about 20 and 150 ° C, preferably 50 may be up to 100 ⁰ C. Inert solvents such as tetrahydrofuran, dioxane or aromatic hydrocarbons such as benzene, toluene, xylene or anisole, dimethylformamide, dimethyl sulfoxide or solvent mixtures of these components are suitable as reaction media. Basic condensing agents that can be used are, for example, sodium aiside, potassium amide or sodium hydride.

The synthesis of the compounds of Formula IV is preferably so carried out that the condensed azlactone II at 6O to 80 ° C in the presence of sodium hydride with acetone dicarboxylic acid monomethyl

509816/121 1 BAD OFHOfNAL

* a. ι s

ester-H ~ alkylmonoamide converts in the absence of oxygen.

The course of the reaction can be followed by chromatography, e.g. thin layer chromatography on silica gel plates which are marked with 5/6 EDTA solution were sprayed. Benzene, for example: ethyl acetate! Formic acid = 10: 3: 1

For isolation, the reaction equipment is acidified with mineral acids or organic acids to a pH of about ^ - 6 and washed out with water. After the solvent has been removed, a mixture of stereoisomeric tetracyclines is obtained which rearranges when standing for several days, preferably 4 days at room temperature, for example in pyridine with the exclusion of light and oxygen. The rearrangement can be accelerated, for example, by slightly increasing the temperature other organic bases with comparable basicity and dissolving power can also be used for the rearrangement, such as picolines, lutidines, collidines, triethylamine, diisopropylamine or tributylamine The rearrangement leads to an increase in the yield of product IV.

After evaporation of the pyridine or the other for rearrangement base used is obtained after treating the residue

: en

for example with 'acetone the crystalline compound of formula IV as d, l-forms.

Die.Hydroxylierung in 12a-position is carried out using molecular oxygen in the presence of strong bases, such as sodium amide, Kaliuittamid, potassium tert-butoxide, preferably sodium hydride and reducing agents that destroy peroxides, such as platinum, palladium, alkali metal ascorbates, mercaptans or Sulphides, preferably trialkyl phosphite, especially triethyl phosphite, in an inert, aprotic polar solvent such as dimethylformamide, tetramethylurea or hexamethylphosphoric acid trisamide at a reaction temperature between -30 and 40 ° C., in particular 15 and 30 ^° C.

509816/121 1 ORIGINAL BATHROOM

The hydroxylation is preferably carried out with molecular oxygen at room temperature in the presence of sodium hydride and with addition of triethyl phosphite. It is sometimes to initiate the reaction necessary to add a few drops of water to the reaction mixture ».

Working up is carried out, for example, by acidification to a pH of 3 to k, concentration of the solution, taking up in an organic solvent, such as, for example, chloroform, washing with water and renewed concentration of the solution.

The hydroxylated tetracycline V can be determined by column chromatography, for example, on silica gel buffered with primary phosphates. Chloroform, for example, is suitable as solvent: Acetone = 4: 1.

The benzoyl group can be split off by methods known from the literature, preferably via the corresponding imino ether. This can be prepared, for example, with strong alkylating agents, in particular with oxonium salts, preferably triethyloxonium tetrafluoroborate. In this case, the procedure is advantageously such that ₉ is allowed to act the oxonium salt in the dark at room temperature to the solution of V in an organic solvent, for example chloroform, dioxane, tetrahydrofuran or methylene chloride. The oxonium salt can be used in stoichiometric amounts or in excess. The excess is destroyed after the reaction by hydrolysis, for example with dilute sodium carbonate solution. Without isolating the imino ether formed, it can be converted into the free amino compound of the formula VI by hydrolysis with dilute mineral acids, such as hydrochloric acid or sulfuric acid, in one of the solvents described above.

Cl

CONHR-

(VI)

509816/1211
BADORtGSNAt.

be split.

The protective group R is split off in a manner known per se, by hydrolytic or hy drogenolytic routes. In principle, all processes known for such reactions can be used here. The tetrahydropyranyl radical and the acyl and alkyl groups can easily be split off, for example, by the action of acids or ansolvo acids such as HBr, HJ and BF- in the presence of an organic solvent, preferably glacial acetic acid. Splitting off is also easy with aqueous acids. The reaction mixture is expediently heated. The temperature can vary from JJO ⁰ C to the boiling point of the solvent. After dilution with water, the reaction products of the formula I with R = Cl with a suitable organic solvent, such as ethyl acetate, methylene chloride, chloroform, benzene or n- Extracted butanol and obtained from the organic phase in the usual way after evaporation of the solvent.

If R ^ is a benzyl or carbobenzoxy group, so can these residues in the usual way by hydrogenolysis, e.g. by treatment with hydrogen in the presence of noble metal catalysts, preferably PtO_ or palladium carbon, in an organic Remove solvents, preferably alcohols.

If acids are used to split off the protective group R ^, so the corresponding acid addition salts are obtained after work-up.

2
The compounds of the formula V with R = H are obtained by hydrogenolytic cleavage of the halogen atom at room temperature in an organic solvent with the addition of an organic base, preferably triethylamine, this step being carried out before the protective groups are removed. All customary hydrogenation catalysts, such as, for example, palladium, platinum, Raney nickel, can be used as catalysts. The hydrogenolysis is preferably carried out with the Pd-Mohr.

509816/1211 BATH ORIGINAL

As physiologically compatible salt formers of the inventive Products of the formula I are, for example, mineral acids, such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acids, boric acid, and organic acids such as Acetic acid, lactic acid, citric acid, maleic acid, succinic acid, ■ malic acid and tartaric acid.

The organic salt formers can also themselves have pharmaceutical activity, such as penicillins, in particular penicillin G and V as well as carbenicillin, cephalosporins, pantothenic acid, chloramphenicol hemisuceinate, salicylic acid, ascorbic acid and nalidixic acid. ^:

The salts can be prepared, for example, by adding stoichiometric amounts of the components in a polar Solvents such as water, alcohol, dimethylformamide, wherein the salt either precipitates or can be isolated by evaporation, lyophilization or precipitation.

The compounds which can be prepared according to the invention are new and valuable Antibiotics. The peculiarity is that by N-substitution of the carbamyl group in the 2-position by alkyl groups, and by substituting an amino group for the dimethylamino group the activity against gram-positive and gram-negative bacteria is fully retained and, surprisingly, the resistance is broken. .

Because the resistance of bacteria to antibacterial substances continues to increase, there is an urgent need to develop new resistance-breaking antibiotics. The minimum Table 1 shows inhibitory concentrations of a new compound in comparison with tetracycline on germs which are resistant to tetracycline are:

509816/1211

> * ϊ ί ί ·

· # ■% 3 a β t ϊ ·

a ι ι

T a b el 1 e 1 r "

Minimal henm concentrations ₍ .

(/ VmI) germ

Tetracycline x HCl I (R ¹ = CH ₃ ; R ² = Cl)

χ HBr

Stäph, aureus 285 125.0 Ο.31

Staph. Whore us 503 125 "0 0.625"

. The minimum Hemra concentrations were determined in a serial dilution tray certainly.

Another great advantage of these connections is their stability. In contrast to tetracycline, they do not rearrange to H-epi compounds in the physiological range, so that it is also possible to produce stable, liquid, pharmaceutical preparations.

The compounds according to the invention are used for the preparation of orally or parenterally administrable preparations for the treatment of bacterial infections. The single dose depends on the type and severity infection and can for example be between about 2 and 20 mg / kg, preferably 3 and 10 mg / kg.

All medical preparations come, for example, tablets, coated tablets, Capsules, solutions under consideration, in addition to the products of the process also the usual auxiliary and carrier substances such as talc, starch, milk sugar, May contain tragacanth or magnesium stearate. It is also possible to use the procedural products bit other chemotherapeutic agents, such as s.B. Antibiotics such as chloramphenicol, amphotericin, etc .; Sulphonamides ^ nitrofurans «u combine.

Compounds of the formula I which can be prepared according to the invention can for example, the compounds listed in the tables below are mentioned, those in Table I being particularly special are preferred. The constitution of the respective compound results .sich directly in connection with the general formula I.

509 816/1211

HO

• ι «

Vf

H IJ> OH

OH β OONHR-OH Ö

Table I.

H
Cl

C ₂ H ₅

Table II

Cl Br

η-C ₃ H ₇ 1-C ₃ H ₇ η-Ο _ή Η ₉ i- ^c l, ^H 9 sec-CjuHg ^ C ₃ H ₇ iC ₃ H ₇ nC, H _g ¹ 7 ° l | ^hJ 9 see.-CkH-

CH ^

n-C H

1-C ₃ H ₇ -UC ₄ H ₉ -> _P TI

^{1 U} 1} ^H 9 sec.-Ci ₁ H,

50 9816/1211

R ¹ 5 CH ₃ 3 ^H 7 U ₂ H 3 ^H 7 n-C 4 ^H 9 i-C ii ^H 9 n-C * " ^C A i-C sec

509816/1211

,Example 1 In*

Acetone dicarboxylic acid monomethyl ester N-methyl half ainide

a. ^ -N-Methylearboxamido ^ -N-methylamino-butene - ^ - methyl esters.

l6O g Acetondicarbonsäuredimethy! ester is dissolved in i liter of methanol and cooled to 1O ° C. Methylamine is passed in for 3 hours, during which the temperature rises to 20 to 23 ° C. and a colorless precipitate separates out. It is then left to stand at 0 to 5 ° C. until the precipitate has dissolved. The solution turns a brownish violet color. The solution is concentrated to about 300 ml. 10 ml of ethyl acetate are added to the violet oil while stirring vigorously, a brown oil separating out. The ethyl acetate solution is filtered through 2 × 10 g silica gel and rinsed with ethyl acetate. The pale yellow solution is concentrated _$ a light yellow crystal slurry remains which is recrystallized in absolute ethanol *,

Yield: 65 g (3 ** % of theory ), pp .: 125 to 127 ° C

b. Acetone dicarboxylic acid monomethyl ester-N ^ methyl half-amide

In a 1 liter two-necked flask equipped with a stirrer, 40 g (0.215 mol) of enamine are dissolved in 50 ml of chloroform. to this solution is allowed to concentrate 15 ml with vigorous stirring. HCl slowly drip. Han lets it stir vigorously for 30 minutes at room temperature. The end of the reaction is determined by IR spectroscopy. The chloroform solution is dried over sodium sulfate and concentrated. Return remains a yellowish oil that crystallizes very slowly when standing. The crude product was used for further reaction.

Yield: 35 g (9 ¹ % of theory )

509816/1211

t Jt

• A-

Example 2

ρ · ζ

Condensation of azlactone II (R = chlorine, R = methyl) with acetone dicarboxylic acid monomethyl ester-N-methyl half-amide to IV (R ¹ and R ³ = methyl; R ² = chlorine)

In a four-necked flask equipped with a reflux condenser, thermometer, gas inlet tube and magnetic stirrer, 20 g <50, i | mmol) azlactone II (R ³ = methyl) and 9.7 g (56th mmol) habamide at HO to 50 ⁰ C (internal temperature) in 300 ml of abs. Tetrahydrofuran (over lithium aluminum hydride and distilled under nitrogen) dissolved. The mixture is then allowed to cool to 15 ° C. and 5 g (166 mmol) of 80% sodium hydride mineral oil paste are added in very small portions, the color changing from colorless to red-brown. The internal temperature must not exceed 20 ° C. The mixture is then refluxed at 70 ° C. for 28 hours. 1 ml of the solution is removed, acidified with 50% acetic acid, diluted with chloroform, extracted four times with water and the chloroform solution is dried over sodium sulfate. After 6 hours, the reaction mixture is acidified to about pH 1 with 50% acetic acid and the tetrahydrofuran is distilled off. The residue is dissolved in chloroform, the solution is washed five times with water, then dried over sodium sulfate and concentrated. The yellow-brown residue is triturated with petroleum ether at 40 to 80 ° C.

Yield: 36 g of orange powder. Mixture of 5 substances, thin-layer chromatography determined (silica gel, sprayed with 5% Titriplex solution _s mobile phase: benzene / ethyl acetate / formic acid 10: 3: 1) Rf value: O _s 92 _s O _s 8l ₉ O ₉ 69, O ₉ ^ II, O _s 23 36 g of tetracyclic mixture are dissolved in 270 ml of pyridine under Np. The solution is left to stand protected from light for 4 mg. The pyridine is completely suctioned off in a high vacuum and the residue is dissolved in a little acetone, with IV crystallizing out »

Yield 9 β (33, * % of theory). Fp .: 260 to

Example 3 * * ■

Hydroxylation of IV (R ¹ , R ⁵ = methyl, R ² = chlorine) to V (R ¹ , R ⁵ = Me thyI, R ² = chlorine)

2 g (3.6 mmol) of (IV) are dissolved in 120 ml of dimethylformamide, bubbling through the solution with nitrogen. 0.6 ml of triethylene phosphite and 480 mg (16 mmol) are added. 80% sodium hydride added. The solution turns orange-red. Oxygen is then introduced and 20 drops of water are added, whereby the solution foams up vigorously. The solution slowly darkens and a precipitate forms. The reaction is complete when, after adding a drop of the reaction solution to 0.1 M methanolic sodium tetraborate solution, it remains colorless or very pale yellow in color and no more fluorescence occurs. After approx. 5 minutes (IV) has reacted, nitrogen is passed through the solution again and the pH is adjusted to 3 to H with 50% acetic acid. It is then concentrated in a high vacuum. The residue is taken up in chloroform, washed four times with water and dried over sodium sulfate. The chloroform solution of 3 batches (a total of 6 g (IV) reacted) is concentrated, and the residue, a dark oil, is dissolved in hot ethyl acetate A precipitate (2.31 g) is filtered off for 3 days at 0-5 ° C., the ethyl acetate solution is concentrated, the residue is taken up in a very little chloroform and separated on a silica gel column (approx. 250 g). Chloroform / acetone is used as the eluent H: 1. The silica gel is pretreated as follows:.

The silica gel is slurried with half-concentrated hydrochloric acid, left to stand for four hours, washed neutral and rinsed with 0.1 M KHpPO ^ solution. It is ^{dried at 200 °} C. and bottled hot. "

Yield: 980 mg (V) (R ¹ , R ³ = methyl, R ² = chlorine) (16 % 'ά .. Th.) Mp .: 211 to

50 9816/1211

Example 4 - _# * T *

Debenzoylation of V (R ¹ , R ⁵ = methyl, R ² = chlorine) see VI (R ¹ , R ³ = methyl, R ² = chlorine)

950 mg (1.72 mmol) of (V) are dissolved in 50 ml of methylene chloride. This solution is added to a solution of 1.3 g of ether-moist triethylbxonium tetrafluoroborate in 50 ml of methylene chloride. This mixture is left to stand for three days at room temperature, protected from light. Then an excess of 5% sodium carbonate solution is added and the mixture is stirred vigorously for half an hour at room temperature. The organic phase is separated off, dried over sodium sulfate and concentrated. The residue is dissolved in 50 ml of tetrahydrofuran and mixed with 32.4 ml of 2N HCl (temperature ^ 15 ° C). The solution is left to stand for 3 1/2 hours at room temperature. It is then diluted with 100 ml of chloroform and washed three times with water / water, the aqueous phase turning yellow. The aqueous phase is extracted with n-butanol until the n-butanol remains colorless. The butanolisehe solution is concentrated in a high vacuum. The green-yellow residue consists of clean (VI) (R ¹ , R ³ = methyl, R ² = chlorine). TLC (cellulose, mobile phase: 0.1 η HCl) -: Rf value 0.52 Yield 390 mg (46.8 % of theory ) Pp .: from 210 ° C decomp.

Example 5

Ether cleavage of the compound (VI) (R ¹ , R ³ = methyl, R ² = chlorine) to djl-desmethyl-ö-desoxy ^ -desdimethylamino ^ -descarbamyl ^ - amino ^ 2-N-methy * lcarbamyl-7-chlorotetracycline I (R = methyl, R ² = chlorine)

60 mg (VI) are dissolved in 8 ml of 48% hydrobromic acid and Refluxed under nitrogen on the steam bath for 35 minutes. The solution is then allowed to cool and diluted with 30 ml of ice water. The solution is extracted with n-butanol until the n-butanol remains colorless.

509816/121 1

■ -Ί5! .-

The alcohol phases are combined and washed three times with water. The butanol is concentrated in a high vacuum, the residue in methanol dissolved and again concentrated in the vacuum. This is repeated several times . .

Yield: 50 mg (78 JfH. Th.) Pp .: 240 to 2 * J5 ° C Eers. TLC (cellulose, 0.1 η HCl): Rf value. O ^.

Mass spectrum m / e = ^ 3 ¹ J

UV spectrum / \ max, nm

225 (17800), 2 «* 5 (sh 16100), 266 (16100), (11300) in 0.1 molar methanolic sodium borate solution

Example 6

«Λ -z

1 "" 5 2

Hydrogenolysis of V (R, R ^ s methyl, R -e chlorine) su V

(R ¹ ZR ³ = methyl, R ² = hydrogen). '

2 mg of V (R ¹ , R ⁵ = methyl, R = chlorine) are dissolved in 10 ml of tetrahydrofuran, 3 drops of triethylamine and 2 microspatula tips of Pd-Mohr are added. It was hydrogenated at room temperature for a time, was completely reacted until the starting product by thin layer chromatography control * Rf value of the final product: 0 _s i5i (silica gel with 5 figer Titriple ^ - solution sprayed; Lauf'mittel 'benzene, - Essigester (10 : 3: 1)

09816/121

Claims (5)

HOE IJ 6-J) c £ * .roethyl-6-deoxy tetracycline of the formula I. K ¹ Ii H Z .OH CONIIR (D in the R "'alkyl with 1 to 4 carbon atoms, preferably methyl and ethyl j and R "denotes halogen, preferably chlorine, and hydrogen, as well as their salts with physiologically acceptable acids. 2. A compound according to claim 1, characterized in that R ^{1 is} methyl and R ^{2 is} chlorine. 3. Process for the preparation of the compounds of the formula I according to the invention, characterized in that an azlactone is used 2 3 Formula II, in which R is halogen, preferably chlorine, and in which R "^ Hydrogen, an alkyl or acyl radical with 1 to 5 carbon atoms, an aroyl radical, a tetrahydropyranyl, benzyl or Carbobenzoxy radical means in the presence of strongly basic condensing agents with acetone dicarboxylic acid ester monoamides of the formula III, in which R has the above meaning, converts to compounds of the formula IV, ' -ir ^^ Il III 509816/1211 BATH ORIGINAL OR NHCOC _r Il _r 6 5 η η; Oh OH O CONHR OR HOE _: 6 5 WlHR ¹ IY these are bydroxyliert with oxygen, by hydrolysis or Hydrogenolysis of the benzoyl protecting group and the protecting group R die Tetracycline of the formula I is obtained, with in the case of an introduction of R = hydrogen, the intermediate stage V before the cleavage of the Protecting groups is dehalogenated by hydrogenolysis. 4. Pharmaceutical preparations effective against bacterial infections, characterized by a content of a compound according to Claim 1 or its physiologically acceptable salt. 5. Process for the production of pharmaceutical preparations ₃ effective against bacterial infections, characterized in that a compound according to claim 1 or its physiologically tolerable salt is brought into a pharmaceutically suitable administration form, if appropriate in a mixture with conventional pharmaceutically acceptable carriers. 509816 / .121 1 ORIGINAL BATHROOM