CA2251813A1 - 5,6,7,8-tetrahydropyrido[2,3-d]pyrimidines - Google Patents

Abstract

Glutamic acid derivatives in which the amino group is substituted with a 2amino-5,6,7,8-tetrahydropyrido¢2,3-d!pyrimidin-6-ylalkyl-Z-carbonyl group, in which Z is a divalent, five-membered, nitrogen-containing heterocyclic ring system optionally containing a sulfur or nitrogen atom as a second hetero ring member, are antineoplastic agents. A typical embodiment is N-{3-¢2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido¢2,3-d!pyrimidin-6-yl)ethyl!-pyrazol-5-ylcarbonyl}-L-glutamic acid.

Description

CA 022518l3 l998-l0-l3 W O97/41115 PCT~US96/14822 S,6,7,8-TETRAHYDROPYRIDO[2,3-~PYRIMIDINES
This invention relates to 5,6,7,8-tetrahydropyrido[2,3-d~pyrimidines of the formula:

R

R3~ N

in which R' is hydroxy or amino;
R2 is hydroxy or a carboxylic acid protecting group;
R3 is hydrogen or an amino protecting group;
10Z is a divalent, five-me~lbered, nitrogen-cont~inin~ heterocyclic ring system optionally co~ ;t)il~g a sulfur or nitrogen atom as a second hetero ring member, the valence bonds origin~ting from nonadjacent carbon atoms of the heterocyclic ring; and n has a value of 2 or 3.
15The present invention also pertains to the pharm~ceutic~lly acceptable salts of the 5,6,7,8-tetrahydropyrido[2,3-a~pyrimidines of Formula I.
In addition, the invention pertains to a method of inhibiting neoplastic growth in a m~mm~l in which the growth is dependent on folic acid, or a metabolic derivative of folic acid (such as N5,N'0-methylenetetrahydrofolate), as a substrate. The method 20 comprises ~dmini~tering, in a single or multiple dose regimen, an effective amount of a compound according to Forrnula I to a mammal in need of such therapy.
Finally, the invention pertains to pharm~ceutical compositions for inhibiting such neoplastic growth in a m~mm~l through inhibition of folate enzymes which comprises a compound according to ~orrnula I in combination with a pharm~ce~ltic~lly acceptable 25 carrier.

CA 022~1813 1998-10-13 The compounds of Forrnula ~ are named herein as derivatives of the pyrido[2,3-d]-pyrimidine fused ring system which is numbered as follows:

N~q 6 2 I~N N 7 It will be appreciated that the pyrido[2,3-d]pyrimidines of Formula I are the 5 tautomeric equivalent of the corresponding 3-H-4-oxo or 3-H-4-imino structures. For simplicity's sake, the compounds are depicted herein as 4-hydroxy and 4-amino com-pounds, it being understood the corresponding and tautomeric keto and imino structures, respectively, are fully equivalent; e.g:

H'N~ _ N~

The compounds of Formula I can be employed in the form of the free dicarboxylic acid, in which case both R2 groups are hydroxyl. Alternatively, the compounds often can be employed in the form of a pharm~ceutic~lly acceptable salt, in which case the hydrogen atom when R2 is hydroxy is replaced by a pharm~ceutically acceptable cation. Such salt forms, including hydrates thereof, are often crystalline and advanta-15 geous for forming solutions or forrn~ ting pharm~ce~ltic~l compositions. Pharmaceut-ically acceptable salts with bases include those formed from the alkali metals, alkaline earth metals, non-toxic metals, ammonium, and mono-, di- and trisubstituted amines, such as for example the sodium, pot~scillm~ lithium, calcium, m~gneSillm' ~lllminllm zinc, ammonium, trimethylammonium, triethanolammonium, pyri~lini~m and 20 substituted pyridinium salts. The mono and disodium salts, particularly the disodium salt, are advantageous.
In addition to the center of chirality about the carbon atom on the glutamic acid design~ted *, a second chiral center is present in the 6-position of the 5,6,7,8-CA 022~1813 1998-10-13 W O97/41115 PCTrUS96/14822 tetrahydropyrido[2,3-d]pyrimidine ring system. Both the therapeutically active diastereomeric mixtures and the individual diastereomers are included in the scope of this invention. When both individual diastereomers are formed, they can be separated mechanically as by chromatography or chemically by forming salts with a chiral acid, 5 such as the individual enantiomers of 10-camphorsulfonic acid, camphoric acid, alpha-bromocamphoric acid, tartaric acid, diacetyltartaric acid, malic acid, pyrrolidone-5-car-boxylic acid, and the like, and then freeing one or both of the individual diastereomeric bases, optionally repeating the process, so as obtain either or both substantially free of the other; i.e., in a form having an optical purity of >95%.
The protecting groups decign~ted by R2 and R3 utilized herein denote groups which generally are not found in the final therapeutic compounds but which are in-tentionally introduced at some stage of the synthesis in order to protect groups which otherwise might be altered in the course of chemical manipulations. Such protecting groups are removed at a later stage of the synthesis and compounds bearing such pro-15 tecting groups thus are of importance primarily as chemical intermediates (although some derivatives also exhibit biological activity). Accordingly the precise structure of the protecting group is not critical. Numerous reactions for the formation and removal of such protecting groups are described in a number of standard works incllldin~, for example, "Protective Groups in Organic Chemistry", Plenum Press, London and New 20 York, 1973; Greene, Th. W. "Protective Groups in Organic Synthesis", Wiley, New York, 1981; "The Peptides", Vol. I, Schroder and Lubke, Ac~dçmic Press, London and New York, 1965; "Methoden der org~ni~chen Chemie", Houben-Weyl, 4th Edition, Vol.15/I, Georg Thieme Verlag, Stuttgart 1974, the disclosures of which are incorporated herein by reference.
With respect to R2 a carboxy group can be protected as an ester which is selectively removable under sufficiently mild conditions not to disrupt the desired structure of the molecule, especially a lower alkyl ester of 1 to 12 carbon atoms such as methyl or ethyl and particularly one which is branched at the 1- or a position such as t-butyl; and such lower alkyl ester substituted in the 1- or 2-position with (i) lower alkoxy, such as for example, methoxymethyl, l-methoxyethyl, and ethoxymethyl, (ii) lower alkylthio, such as for example methylthiomethyl and l-ethylthioethyl; (iii) halogen, such as 2,2,2-trichloroethyl, 2-bromoethyl, and 2-iodoethoxycarbonyl; (iY) one or two phenyl groups each of which can be unsubstituted or mono-, di- or tri-substituted with, for example lower alkyl such as tert.-butyl, lower alkoxy such as methoxy, hydroxy, halo such as chloro, and nitro, such as for example, benzyl, 4-nitrobenzyl, diphenylmethyl, di-(4-methoxyphenyl)methyl; or (v) aroyl, such as CA 022~1813 1998-10-13 phenacyl. A carboxy group also can be protected in the form of an organic silyl group such as trimethylsilylethyl or tri-lower alkylsilyl, as for example tri-methyl-silyloxycarbonyl .
With respect to R3, an amino group can be protected as an amide u~ili7.ing an acyl group which is selectively removable under mild conditions, especially formyl, a lower alkanoyl group which is branched in 1- or a position to the carbonyl group, particularly tertiary alkanoyl such as pivaloyl, or a lower alkanoyl group which is substituted in the position a to the carbonyl group, as for example trifluoroacetyl.
In the compounds of Formula ~, Z is a divalent, five-membered, nitrogen-0 cont~ining heterocyclic ring system. Optionally the ring may cont~ining a sulfur or nitrogen atom as a second hetero ring member. The depicted valence bonds of Z
originate from nonadjacent carbon atoms of the ring. Z thus can be, for example,pyrrolediyl, imidazolediyl, pyrazolediyl., thiazolediyl, or isothiazolediyl. It will be appreciated that when the divalent heterocyclic group comprised by Z is asymmetric, as for example pyrrole-2,4-diyl (as contrasted with the symmetrical pyrrole-2,5-diyl), the single group can be oriented in either of two ways; e.g, (i) with the -CnH2n- group depicted in Forrnula I in the 2-position and the carbonyl group in the 4- position, or (ii) with the carbonyl group in the 2-position and the -CnH2n- group in the 4- position Particularly preferred compounds are those wherein R2 is hydroxy, R3 is hydrogen, and n has a value of 2; e.g., N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-S-ylcarbonyl}-L-glutamic acid; N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-4-ylcar-bonyl}-L-glutamic acid; N-{4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyl]-pyrrol-2-ylcarbonyl } -L-glutamic acid; N- { 3 -[2-(2-amino-4-hydr-oxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrazol-5-ylcarbonyl}-L-glutamic acid; N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-4-ylcarbonyl}-L-glutamic acid, N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-5-ylcarbonyl}-L-glutamic acid; N-{3-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-isothiazol-5-ylcarbonyl}-L-glutamic acid; N-{5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d~pyrimidin-6-yl)ethyl]-isothiazol-3-ylcarbonyl}-L-glutamic acid; N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-imidazol-4-ylcarbonyl}-L-glutamic acid; N-{2-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-5-ylcarbonyl}-L-glutamic acid; N-3 5 { 2-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-4-CA 022F,1813 1998- lo- 13 ylcarbonyl}-L-glutamic acid; N-{4-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyl]-pyrrol-2-ylcarbonyl~-L-glutamic acid; N-~ 3-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrazol-5-ylcarbonyl} -L-glutamic acid; N-{2-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-4-ylcarbonyl}-L-glutamic acid; N-{2-[2-(2,4-diamino-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-5-ylcarbonyl~-~-glutamic acid; N-{3-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-isothiazol-5-ylcar-bonyl}-L-glutamic acid; N-{5-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyl]-isothiazol-3-ylcarbonyl}-L-glutamic acid; and N-{2-[2-(2,4-diamino-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-imidazol-4-ylcarbonyl}-L-glutamic acid.
The compounds of this invention can be prepared through catalytic hydrogenation of a compound of the formula:
Ol H
N~CY--CY-Z-COR2 II
in which:
Z is as defined above;
R2 is a carboxylic acid p-~lecling group or CH(COR2)CH2CH2COR2 in which R2 s a carboxylic acid protecting group;
R3 is an amino protecting group; and each Y when taken separately is hydrogen or both Y's when taken together are a carbon-carbon bond.
Suitable hydrogenation catalysts include noble metals and noble metal oxides such as p~ ]m or platinum oxide, rhodium oxide, and the foregoing on a support such as 25 carbon or calcium oxide.
When R2~ is -CONHCH(COOR2)CH2CH2COOR2, protecting groups encompassed by R2 and R3 are removed. If on the other hand R2~ is a carboxylic acid protecting group, the R2 protecting group can removed following hydrogenation as CA 022~1813 1998-10-13 described above, and the resulting free carboxylic acid then coupled with a protected glutamic acid derivative in the manner described in U.S. Patent No. 4,684,653, the disclosure of which is incorporated herein by reference, using conventional conden-sation techniques for forming peptide bonds such as dicyclohexylcarbodiimide or 5 diphenylchlorophosphonate. Following this coupling reaction, any r~llAin;
protecting groups are removed.
Protecting groups encompassed by R2, R2, R2, and R3 can be removed through acidic or basic hydrolysis, as for example with sodium hydroxide. Methods of removing the various protective groups are described in the standard references noted 10 above and incorporated herein by reference.
According to the foregoing processes, compounds of Formula II in which R' is hydroxy are obtained. When a compound of Formula I in which Rl is amino is desired, a compound in which Rl is hydroxy can be treated with 1,2,4-triazole and (4-chloro-phenyl)dichlorophosphate and the product of this reaction then treated with concen-15 trated ammonia.
Compounds of Formula II can be prepared utili7ing the procedures described in U.S. Patent No. 4,818,819, the disclosure of which is incorporated herein by l~relence.
In one embodiment a 6-vinyl- or 6-ethynylpyrido[2,3-d]pyrimidine is allowed to react with a halo-Z-carbonyl compound in the presence of a palladium/trisubstituted 20 phosphine catalyst:
OH
,.
N~CY CYH + X-Z-COR2 R3 HNJ~NJ~N) OH
N ~ CY=CY-Z-COR2 R3 HNJ~N~N~

in which each of R2, R3, Y, and Z is as defined above and X is bromo or iodo. The 6-vinyl- and 6-ethynylpyrido[2,3-d]pyrimidine intermediates are known chemical intermediates being described, for example, in U.S. Patent No. 4,818,819, noted supra.

CA 022~1813 1998-10-13 W O 97/41115 PCTrUS96/14822 Alternatively, a 6-bromo- or 6-iodopyrido[2,3-d]pyrimidine intermediate is allowed to react with a vinyl or ethynyl derivative of the heterocycle comprised by Z, again in the presence of the same p~ m/trisub5tituted phosphine catalyst:
S)H
N~X + HCYzCY-Z-COR2 R3 HN N N~ N ~CY=CY-Z-COR2 R3 HNlNg~N

S in which each of R2, R3, Y, X, and Z is as defined above. Both the 6-bromo- or 6-iodopyrido[2,3-d]pyrimidine intermediates and pall~lium/trisubstituted phosphine cata-lyst again are described in U.S. Patent No. 4,818,819, noted supra.
The heterocyclic starting materials either are known or can be made through a variety of conventional techniques. For example, vinyl-Z-COR2 intermediates can be 10 obtained from the corresponding aldehydes through lre~.l."e~l with methyltriphenylphosphonium bromide and lithium hexamethyl~ 7ide in tetrahydrofuran. Alternatively a vinyl-Z-H compound can be carboxylated, as for example with ethyl chloroformate and n-butyllithium. The X-Z-COR2 compounds can be obtained through halogenation of a heterocylic carboxylate, e.g, H-Z-COR2, 15 utili7ing conventional halogenation reagents such as N-bromosllccinimide or N-iodosuccinimide. In any of these routes, compounds carrying a substitutable ringnitrogen atom in the heterocyclic system can be protected through prior formation of the corresponding N-trityl compound or N-triisopropylsilyl compound.
The compounds of this invention have an effect on one or more enzymes which 20 utilize folic acid, and in particular metabolic derivatives of folic acid, as a substrate.
The action of the compounds appear to be similar in this regard to that of 5,10-dideazatetrahydrofolic acid which is described in U.S. Patent No. 4,684,653. Thus the compounds exhibit particularly strong inhibitory activity against the enzyme glycinamide ribonucleotide formyltransferase. The compounds also exhibit inhibitory 25 activity against folate enzymes such as dihydrofolate reductase and thymidylate synthet~e. Representative IC50 values for example against human T-cell derived Iymphoblastic leukemia cells (CCRF-CEM), for (i) N-{4-[2-(2-amino-4-hydroxy-CA 022~1813 1998-10-13 5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-2-ylcarbonyl~-L-glutamic acid, (ii) N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido,r2,3-d]pyrimidin-6-yl)ethylJ-pyrrol-4-ylcarbonyl}-L-glutamic acid, (iii) N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido,r2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-5-ylcarbonyl}-L-glutamic acid, and (il~) N- { 3-[2-(2-amino-4-hydroxy-5,6,7, 8-tetrahydropyrido[2,3 -d]pyrimidin-6-yl)ethyl]-pyrazol-5-ylcarbonyl}-L-glutamic acid are (i) 0.024 Il/m~, (ii) 0.008 Il/mL, (iii) 0.009 ~l/mL, and (iv) 0.0019 ,~l/rnL.
The compounds can be used, under the supervision of qualified professionals, to inhibit the growth of neoplasms including choriocarcinoma, leukemia, adenocarcinoma 10 of the female breast, epidermic cancers of the head and neck, squamous or small-cell lung cancer, and various Iymphosarcomas. The compounds can also be used to treatmycosis fungoides, arthritis, and psoriasis. The compounds can be a(lministered orally but preferably are a~lministered parenterally, alone or in combination with other thera-peutic agents including other anti-neoplastic agents, steroids, etc., to a ~ ,--"~l 15 suffering from neoplasm and in need of treatment. Parenteral routes of administration include intr~mllsc~ r, intrathecal, intravenous and intra-arterial Dosage regimçn~
must be titrated to the particular neoplasm, the condition of the patient, and the response but generally doses will be from about 10 to about 100 mg/day for 5-10 days or single daily at1mini~tration of 250-500 mg, repeated periodically; e.g. every 14 days.
20 While having a low toxicity as compared to other ~ntimet~bolites now in use, a toxic response often can be Plimin~ted by either or both of redll.-in~ the daily dosage or a.~lministering the compound on alternative days or at longer intervals such as every three days. Concomitant a~lmini~tration of folic acid as a rescue therapy also may be indicated. Oral dosage forms include tablets and capsules cont~ining from l-10 mg of 25 drug per unit dosage. Isotonic saline solutions cont~ining 20-100 mg/m~ can be used for parenteral af~ ion.
The following examples will serve to further illustrate the invention.

Methods and Materials Tetrahydrofuran was distilled from sodium/benzophenone; dimethylform~mide and 30 acetonitrile were distilled over calcium hydride. All reactions in these solvents were conducted under positive pressure of an inert gas. Column chromatography was car-ried out with Merck grade 60 silica gel (230-400 mesh). N~R spectra (250 or 300 MHz) were recorded using CDCl3, CD30D, or DMSO-d6 as solvents and internal standards. In the NMR data, "s" denotes singlet, "d" denotes doublet, "t" denotes CA 022~1813 1998-10-13 W O97/41115 PCT~US96/14822 triplet, "q" denotes quartet, "m" denotes multiplet, and "br" denotes a broad peak.
Melting points are uncorrected.
EXAMPLE I
Methyl 4-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-dlpyrimidin-6-yl)ell.y.. yl]-1-tri-isopropylsil~ly~ . ole-2-carboxylate A mixture of 3-iodo-5-methoxycarbonyl-1-triisopropylsilylpyrrole (1.222 g, 3.0 mmol), 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine (0.851 g, 3.15mmol), Pd(PPh)2C12 (105 mg, 0.15 mmol), cuprous iodide (2g mg, 0.15 mmol), and triethylamine (0.5 mL) in acetonitrile (50 mL) was heated at reflux for 4 hours. The resulting solution was cooled, filtered, and concentrated in vacuo. The residue was purified by flash chromatography, eluting with hexanes:ethyl acetate(2:1). The first major fraction is unchanged starting material (270 mg, 32%); the subsequent major fluorescent fractions were combined and concentrated i71 vacuo to give methyl 4-l2-(2-pivaloylamino-4-hydl o~y~lyrido[2,3-dlpyrimidin-6-yl)ethynyl]- 1 -triisopropylsilylpyrrole-2-carboxylate as a pale yellow solid (935 mg, 57%, mp 163-165~C): IH NMR (CDC13) ~ 8.90 (br s, 1 H), 8.52 (d, I H, J = 2.4Hz), 7.35 (d, 1 H, J
= 1.4Hz), 7.23 (d, 1 H, J= 1.4Hz), 3.79 (s, 3 H), 1.75 (sept, 3 H, J = 7.6Hz), 1.31 (s, 9H), 1.10(d, 18H,J=7.6Hz).
Anal. Calcd for C29H39N5O4Si: C, 63.36; H, 7.15; N, 12.74. Found: C, 63.14;
H, 7.12; N, 12.62.
The 3-iodo-5-methoxycarbonyl-1-triisopropylsilylpyrrole starting material can beprepared as follows. Sodium hydride (80% dispersion; 660 mg, 22 mmol) was washedwith pentane and suspended in tetrahydrofuran (20 mL). A solution of methyl pyrrole-2-carboxylate (1.251 g, 10 mmol) in tetrahydrofuran (10 mL) was added and the mixture stirred at room temperature. When gas evolution ceased, triisopropylsilyl chloride (1.928 mg, 10 mmol) was added dropwise, and the mixture was stirred for 1 hour, heated at reflux overnight, and partitioned between ether and water. The ethereal layer was dried (magnesium sulfate) and concentrated in vacuo. The residue was purified by chromatography using hexanes:ethyl acetate (8:1) to yield 2-methoxycarbonyl-l-triisopropylsilylpyrrole as an oil (2.05 g, 73%): ~H NMR (CDC13) o 7.12 (m, 2 H), 6.26 (m, 1 H), 3.78 (m, 3 H), 1.76 (sept, 3 H, J = 7.6 Hz), 1.04 (d, 18 H, J = 7.6 Hz).
Anal. Calcd for C15H27NO2Si: C, 64.01; H, 9.67; N, 4.98. Found: C, 64.30; H, 9.96; N, 4.72.

~ . , , CA 022~1813 1998-10-13 W O 97/41115 PCTrUS96/14822 N-Iodosuccinimide (653 mg, 2.9 mmol) was added to a stirred solution of 2-methoxycarbonyl-l-triisopropylsilylpyrrole (815 g, 2.9 mmol) in tetrahydrofuran (20 mL). The reaction mixture was stirred at room temperature for two days. The solvent was then removed in vacuo and the oily residue suspended in hexanes (S0 mL) withvigorous stirring. The insoluble solid was removed by filtration and the filtrate concentrated in vacuo. Purification of the residue by column chromatography using hexanes gave 3-iodo-S-methoxycarbonyl-l-triisopropylsilylpyrrole (1.044 g, 88%) as a white crystalline solid, mp 81-83~C: ~H N~ (CDC13) ~ 7.18 (d, 1 H, J = 1 5 Hz), 7.09(d,1H,J=l.SHz),379(s,3H),1.74(sept,3H,J=7.6Hz), l.ll(d,18H,J=
10 7.6 Hz).
Anal. Calcd for C15H26IN02Si: C, 44.23; H, 6.43; N, 3.44. Found: C 44 00; H
6.53; N, 3.43.

Methyl 4-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyll-1-triisopropylsil~ le-2-carboxylate A mixture of methyl 4-[2-(2-pivaloylamino-4-hydroxypyrido~2,3-dlpyrimidin-6-yl)ethynyl]-1-triisopropylsilylpyrrole-2-carboxylate (550 mg, 1.0 mmol) and 10%
20 p~ dillm-on-carbon (220 mg) in methanol (45 mL) was stirred overnight under hydrogen (50 psi). The reaction mixture was filtered through Celite and the filtrate concentrated in vacuo. The residue was dissolved in methylene chloride and filtered through a short silica gel column. The eluate was evaporated to give methyl 4-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-1 -25 triisopropylsilylpyrrole-2-carboxylate (524 mg, 94%). The analytical sample, mp 202-204~C, was obtained by column chromatography using chloroform:methanol (19: 1):
lH NMR (CDC13) ~ 11.34 (br s, 1 H), 7.85 (br s, 1 H), 6.98 (s, 1 H), 6.90 (s, 1 H), 4.69 (s, 1 H), 3.79 (s, 3 H), 3.36 (br d, 1 H, J = 10.0 Hz), 2.99 (m, 1 H), 2.83 (m, 1 H), 2.59 (m, 2H), 2.12 (dd, 1 H, J = 15.6, 9.0 Hz), 1.90 -l.S0 (m, 6H), 1.30 (s, 30 9H), 1.11 (d, 18H,J=7.6Hz).
Anal. Calcd for C29H47N504Si: C, 62.15; H, 8.49; N, 12.42. Found: C, 62.15;
H, 8.54; N, 12.42.

CA 022~1813 1998-10-13 Ethyl 5-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-dl-pyrimidin-6-yl)ethyll pyrazole-3-carboxylate Reduction of ethyl 5-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)ethenyl]pyrazole-3-carboxylate (820 mg, 2.0 mmol) using p~llatlillm-on-carbon (820 mg) as catalyst as in Example 2 similarly yields ethyl 5-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrazole-3-carboxylate, mp 235-237~C: 'H NMR (DMSO-d6) o 13.25 (s, 1 H), 11.22 (s, 1 H), 10.67 (s, I H),6.47 (s, 1 H), 6.45 (s, 1 H), 4.22 (q, 2 H, J = 7.0Hz), 3.36 (brd, I H, J = 107Hz), 2.83 (m, 1 H), 2.69 (m, 2 H), 2.54 (brd, I H, J = 15.2Hz), 1.90 (dd, 1 H, J = 15.2, 7.9 Hz), 1.72 -1.50 (m, 3 H), 1.26 (t, 3 H, J = 7.0 Hz), 1.25 (s, 9 H). HRMS calcd for C20H28N6O4 416.2172, found 416.2179.
Anal. Calcd for C20H27N6O4: C, 57.82; H, 6.55; N, 20.23. Found: C, 57.64; H, 6.S8 N, 20.61.

Methyl 5-[2-(2-Piv~loylamino-4-hydro~y,oyri~1o[2,3-d]pyrimidin-6-yl)ethenyll pyrrole-2-carboxylate A mixture of methyl 5-vinylpyrrole-2-carboxylate (298 mg, 2.0 mmol), 2-pivaloyl-amino-4-hydroxy-6-bromopyrido[2,3-d]pyrimidine (683 mg, 2.1 mmol), p~
acetate (22.5 mg, 0.1 mmol), tri-o-tolylphosphine (60.9 mg, 0.2 mmol), and triethylamine (7.0 mL) in acetonitrile (20 mL) was heated overnight at reflux. The reaction mixture was cooled to room temperature, and the solid which formed collected by filtration, washed with cold acetonitrile, and dried to give methyl 5-[2-(2-pivaloylamino-4-hydroxypyridol2,3-dJpyrimidin-6-yl)ethenyl]pyrrole-2-carboxylate as a yellow solid (706 mg, 89%). The product can be used in the next step without further purification. An analytical sample, mp >260~C, was obtained by recrystallization from methanol: IH NMR (DMSO-d6) o 12.28 (s, 1 H), 12.08 (s, 1 H), 11.40(s, lH),8.93(s, lH),8.40(s, lH),7.36(d, lH,J=16.6Hz),7.27(d, lH,J
=16.6Hz),6.81(m,1H),6.48(m,1H),3.76(s,3H),1.23(s,9H).
Anal Calcd for C20H2lN5O4: C, 60.75; H, 5.35; N, 17.71. Found C, 60.80; H, 5.36;N, 17.92.

.. ~................................................. .

CA 022~l8l3 l998-l0-l3 W O97/41115 PCTrUS96/14822 EXAMPLE S
Methyl 4-12-(2-Pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)-ethenyl] pyrrole-2-carboxylate Similarly obtained from methyl 4-vinylpyrrole-2-carboxylate (298 mg, 2.0 mmol), 2-pivaloylamino-4-hydroxy-6-bromopyrido[2,3-d]pyrimidine (715 mg, 2.2 mmol), p~ dillm acetate (27 mg, 0 1 mmol), tri-o-tolylphosphine (61 mg, 0.2 mmol), and triethylamine (1.4 mL) according to the procedure of Example 4 is methyl 4-[2-(2-pivaloylamino-4-hydroxypyrido[2,3 -d]pyrimidin-6-yl)ethenyl]pyrrole-2-carboxylate (700 mg, 89%): mp >260~ C: ~I N~ (DMSO-d6) ~ 12.30 (br s, 1 H), 12.06 (s, lH), 11.39(s, lH),8.98(s, lH),8.41 (s, lH),7.31 (d, lH,~=16.5Hz),7.26(s, lH),7.11 (s, lH),7.15(d, lH,J=16.5Hz),3.76(s,3H), 1.25(s,9H).
or C20H21N5O4Ø5 H2O: C, 59.38; H, 5.49; N 17 32 Found: C
59.24; H, 5.33; N, 17.37.

Methyl 5-12-(2-Pivaloylamino-4-hydrox~ , ;dol2,3-dlpyrimidin-6-yl)ethenyl] pyrrol~3-carboxylate Use of methyl 5-vinylpyrrole-3-carboxylate in the same fashion as Example 4 yields methyl 5-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)ethenyl]-pyrrole-3-carboxylate (1.02 g, 86%) mp >260~C: IH NMR (DMSO-d6) ~ 11.95 (br s, lH), 11.06(s, lH),9.76(s, lH),8.86(s, lH),8.33(s, lH),7.51 (s, 1H),7.20(d, 1 H, J = 16.4 Hz), 7.03 (d, 1 H, J = 16.4 Hz), 6.64 (s, 1 H), 3.69 (s, 3 H), 1.2:2 (s, 9H).
Anal. Calcd for C20H21N5O4: C, 60.75; H, 5.35 N, 17.71. Found: C, 60.50; H, 5.27; N, 17.76.
The methyl 5-vinylpyrrole-2-carboxylate starting material is obtained as follows.
To a stirred suspension of methyltriphenylphosphonium bromide (2.358 g, 6.6 mmol) in tetrahydrofuran (50 mL) was added dropwise 1 N lithium hexamethyldisilazide in tetrahydrofuran (6.6 mL, 6.6 mmol) at 0~C. A~er the solution was stirred for 1 hour, methyl 5-formylpyrrole-2-carboxylate (453 mg, 3.0 mmol) was added in one portion to the resulting solution, and the reaction mixture was stirred for 1.5 hours at room temperature, quenched by addition of water (10 mL) and then acidified with 1 N HCI.
The organic phase was dried (magnesium sulfate) and concentrated. Purification of the residue by flash chromatography using hexanes:ethyl acetate (4:1) gave methyl 5-CA 022~1813 1998-10-13 W O 97/41115 PCT~US96/14822 vinylpyrrole-2-carboxylate (400 mg, 90%) as a white crystalline solid, mp 91 -93~C:
~H NMR (CDC13) ~ 9.40 (br s, 1 H), 6.86 (dd, 1 H, J = 3.7, 2.4 Hz), 6.56 (dd, 1 H, J
= 17.8, 11.2Hz), 6.27 (dd, 1 H, J = 3.7, 2.8 Hz), 5.59 (d, 1 H, J = 17.8 Hz), 5.22 (d, lH, 11.2Hz),3.85(s,3H).
Anal. Calcd for C8HgNO2 C, 63.56; H, 6.00; N, 9.27. Found: C, 63.33; H, 6.28;
N, 9.00.
Similarly obtained from methyl 4-formylpyrrole-2-carboxylate (453 mg, 3.0 mmol) and methyltriphenylphosphonium bromide (2.36 g, 6.6 mmol) is methyl 4-vinylpyrrole-2-carboxylate as a white crystalline solid (436 mg, 98%, mp 63-65~C): IH NMR
(CDC13) ~ 9.34 (br s, 1 H), 7.00 (m, 1 H), 6.94 (s, 1 H), 6.54 (dd, 1 H, J = 17.7, 11.0 Hz), 5.43 (dd, 1 H, J = 17.7, 1.2Hz), 5.02 (dd, 1 H, J= 11.0, 1.2Hz).
Anal. Calcd for CgHgNO2 C, 63.56, H, 6.00; N, 9.27. Found: C, 63.38; H, 6.08;
N, 9.27.
Similarly obtained from methyl 5-forrnylpyrrole-3-carboxylate (907 mg, 6 mmol) and methyltriphenylphosphonium bromide (5.71 g, 13.2 mmol) is methyl 5-vinylpyrrole-3-carboxylate, mp 97-99~C: ~H NMR (CDC13) ~ 8.83 (br s, 1 H), 7.36 (s, lH),6.59(s,1H),6.56(dd,1H,J=17.7,11.2Hz),5.35(d,1H,J=17.7Hz),S.ll (d, 1 H, J= 11.2Hz), 3.81 (s, 3 H).
Anal. Calcd for C8HgNO2 C, 63.56; H, 6.00; N, 9.27. Found: C, 63.35; H, 6.10;
N, 9.20.
Similarly prepared from ethyl 5-formylpyrazole-3-carboxylate (1.66 g, 10 mmol) and methyltriphenylphosphonium bromide (7.50 g, 21 mmol) is ethyl 5-vinylpyrazole-3-carboxylate as a white crystalline solid (1.55 g, 95%), mp 75-77~C, 111 NMR
(CDC13) ~ 11.20 (br s, 1 H), 6.89 (s, 1 H), 6.68 (dd, 1 H, J = 17.7, 11.3Hz), 5.76 (d, lH,J=17.7Hz),5.38(d,1H,J=11.3Hz),4.37(q,2H,J=7.2Hz),1.37(t,3H,J=
7.2Hz).
Anal. Calcd for C8HloN2O2: C, 57.82; H, 6.07; N, 16.86. Found: C, 57.66; H, 6.21;N, 17.05.

Ethyl 5-12-(2-pivaloylamino-4-hydroxypyridol2,3-dlpyrimidin-~
yl)ethenyllpyrazole-3-carboxylate From ethyl 5-vinylpyrazole-3-carboxylate (492 mg, 3.0 mmol), 2-pivaloylamino-4-hydroxy-6-bromopyrido~2,3-d]pyrimidine (25, 1.07 g, 3.3 mmol), p~ dillm acetate . ..

CA 022~1813 1998-10-13 W O 97141115 PCTrUS96/14822 (34 mg, 0.15 mmol), tri-o-tolylphosphine (91 mg, 0.3 mmol), and triethylamine (2.1 mL) there is similarly obtained according to the procedure of Example 4, ethyl 5-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d}pyrimidin-6-yl)ethenyl]pyrazole-3-carboxylate (1.04 g, 85%, mp >260~C); ~H NMR (DMSO-d6) o 13.75 (s, 1 H), 12.28 (s, 1 H), 11.42 (s, 1 H), 9.01 (s, 1 H), 8.47 (d, 1 H, J = 2.5Hz), 7.36 (AB, 2 H), 6.96 (s, 1 H), 4.29 (~, 2 H ,J = 7.0Hz), 1.30 (t, 3 H, J = 7.0 Hz), 1.25 (s, 9 H). HRMS calcd for C20H22N6O4 410.1703, found 410.1692.
Anal. Calcd for C20H21N6O4: C, 58.67; H, 5.17; N, 20.53. Found: C, 58.50; H, 5.13 N, 20.44.

Methyl 5-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d]-pyrimidin-6-yl)ethyl] pyrrole-2-carboxylate A mixture of methyl 5-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]-pyrimidin-6-yl)ethenyl]pyrrole-2-carboxylate (593 mg, 1.5 mmol) and platinum oxide (68 mg) in glacial acetic acid (200 mL) was stirred overnight under hydrogen (50 psi). The reaction mixture was filtered through Celite and the filtrate was concentrated in vacuo.
The solid was recryst~lli7.ed from methanol to give methyl 5-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyriînidin-6-yl)ethyl]pyrrole-2-carboxylate as an off-white solid (505 mg, 84%), mp 246-248~C: 'H NMR (DMSO-d6) ~ 11.67 (s, 1 H), 10.90 (br s, 1 H), 10.60 (br s, 1 H), 6.66 (s, 1 H), 6.45 (s, 1 H), 5.91 (s, 1 H), 3.72 (s, 3 H), 3.22 (brd, 1 H, J = 10.5 Hz), 2.81 (m, 1 H), 2.64 (m, 2 H), 2.52 (brd, lH,J=15.2Hz), 1.88(dd, lH,J=15.2,7.9Hz), 1.68-l.50(m,3H), 1.21(s,9H).
Anal. Calcd for C20H27N5O4: C, 59.84; H, 6.78; N, 17.44. Found: C, 59.55; H, 6.79; N, 17.20.

Methyl 4-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d~-pyrimidin-6-yl)ethyl]pyrrole-2-carboxylate Upon reduction of methyl 4-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]-pyrimidin-6-yl)ethenyl]pyrrole-2-carboxylate with hydrogen and palladium-on-carbon catalyst (200 mg) analogously to that described in Example 8, there is obtained methyl 4-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylate (380 mg, 95%): mp 236-238~C: IH N~ (DMSO-d6) o CA 022~l8l3 l998-l0-l3 W O 97/41115 PCTrUS96/14822 11.59 (s, 1 H), 11.21 (s, 1 H), 10.60 (s, I H), 6.81 (s, 1 H), 6.62 (s, 1 H), 6.42 (s, 1 H), 3.7() (s, 3 H), 3.23 (br d, 1 H, J = 10.5 Hz), 2.82 (m, 1 H), 2.57 - 2.43 (m, 3 H), 1.87(dd, lH,J=15.2,8.0Hz), 1.68-1.43(m,3H), 1.18(s,9H).
Anal. Calcd for C20H27N5O4: C, 59.84, H, 6.78; N, 17.44. Found: C, 59.70; H, 6.61; N, 17.65.

Methyl 5-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyllpyrrole-3-carboxylate Similarly prepared as in Example 8 but from methyl 5-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)ethanyl]pyrrole-3-carboxylate is methyl 5-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-3-carboxylate, mp >260~C: IH N~ (CDC13/CD30D, 1/1) ~ 7.22 (s, 1 H), 6.20 (s, lH), 3.71 (s, 3 H), 3.28 (brd, lH, J= 12.1Hz), 2.91 (dd, lH, J = 12.1, 8.7Hz), 2.75-2.55 (m, 3 H), 2.00 (dd, 1 H, J = 15.8, 9.0 Hz), 1.74 (m, 1 H), 1.61 (m, 1 H), 1.21 (s,9H).
Anal. Calcd for C2oH27N5040.5 H20: C, 58.51; H, 6.88; N, 17.07. Found: C, 58.55; H, 6.95; N, 16.90.

4-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic Acid A suspension of methyl 4-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidin-6-yl)ethyl]-1-triisopropylsilylpyrrole-2-carboxylate (390.4 mg, 0.7 mmol) in I N sodium hydroxide (1 mL) was heated under reflux until clear (about 4 hours). The mixture was cooled to room temperature, extracted with ethyl acetate, and then acidified with glacial acetic acid. The solid which formed was collected by filtration, washed with water, and dried in vacuo to give 4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic acid (199 mg, 94%), mp >260~C: lH NMR (DMSO-d6) ~ 11.39 (s, 1 H), 9.72 (br s, I H), 6.73 (s, 1 H), 6.55 (s, I H), 6.25 (s, 1 H), 5.93 (s, 2 H), 3.16 (br d, 1 H, J = 9.5 Hz), 2.72 (m, 1 H), 2.43 (m, 3 H), 1.75 (m, I H), 1.42 - 1.53 (m, 3 H); IH NMR (CD30D) 6.69 (s, I H), 6.63 (s, 1 H), 3.31 (brd, I H, J = 12.1 Hz), 2.91 (dd, I H, J = 12.1, 9.2Hz), 2.67 (dd, 1 H, J = 15.3, 4.4Hz), 2.55 (m, 2 H), l.99 (dd, l H, J = 15.3, 9.4 Hz), 1.76(m, lH), 1.60(m,2H).

Anal. Calcd for C14H17N5O3: C, 55.44; H, 5.65; N, 23.09. Found: C, 55.44; H, 5.84; N, 23.49.

5-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic Acid In the same manner as Example 11 there is obtained from methyl 5-[2-(2-pivaloyl-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl~pyrrole-2-carb-oxylate (401 mg, 1.0 mmol) and lN sodium hydroxide (6 mL), 5-[2-(2-arnino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic acid (257 mg, 85%) as an off-white solid, mp >260~C: lH NMR (DMSO-d6) o 11.34 (s, 1 H), 10.20 (br s, 1 H), 6.50 (s, 1 H), 6.25 (s, 1 H), S.g6 (s, 2 H), 5.87 (s, 1 H), 3.15 (br d, 1 H, J = 10.3 Hz), 2.73 (m, 1 H), 2.63 (m, 2 H), 2.55 (br d, 1 H, J = 14.9 Hz), 1.78 (dd, 1 H, J = 14.9, 7.9 Hz), 1.80 -1.50 (m, 3 H).
or C14H17N5O3 0.5H2O: C, 53.82 H, 5.81; N 22 43 ~ound: C
54.13; H, 5.65; N, 22.19.

5-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-dlpyrimidin-6-yl)ethyl]pyrrole-3-carboxylic Acid Upon saponification of methyl 5-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-3-carboxylate (401 mg g, 1.0mmol) with lN sodium hydroxide (15 mL) as described in Example 11, there is obtained 5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)eth-yl]pyrrole-3-carboxylic acid, mp >260~C: ~H NMR (DMSO-d6) o 11.49 (s, 1 H), 10.12 (brs, lH), 9.66 (s, lH), 7.16 (s, lH), 6.23 (s, lH), 6.05 (s, 2H~, 5.90 (s, I H), 3.16 (brd, 1 H, J = 10.9 Hz), 2.78 (m, 1 H), 2.63-2.40 (m, 2 H), 1.77 (dd, 1 H, J = 15.2, 8.6 Hz), 1.69 -1.43 (m, 3 H).

5-[2-(Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-dlpyrimidin-6-yl)ethyl~pyrazole-3-carboxylic Acid Upon saponification of ethyl 5-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrazole-3-carboxylate (637 mg, 1.5 mmol) with lN
sodium hydroxide (3 mL) as described in Example 11, there is obtained 5-[2-(amino-4-CA 022~1813 1998-10-13 hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrazole-3-carboxylic acid (368 mg, 80%, mp >260~C): ~H NMR (DMSOd6) ~ 12.90 (br s, 1 H), 9.85 (br s, 1 H), 6.67 (s, 1 H), 6.42 (s, 1 H), 6.27 (s, 1 H), 5.96 (s, 2 H), 3.16 (br d, 1 H, J = 107 Hz), 2.74 (m, 1 H), 2.65 (m, 1 H), 2.46 (brd, 1 H, J = 15.0 Hz), 1.90 (dd, 1 H, J =
15.0, 7.9 Hz), 1.68-1.47 (m, 3 H).
Anal. Calcd for C13H16N6O3 1.5 H20: C, 47.13; H, 5.78; N, 25.36. Found: C, 46.82; H, 5.78 N, 24.97.

Dimethyl N-{4-12-(Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6--yl)ethyl]pyrrol-2-ylcarbony}-I~glutamate A solution of 4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic acid (152 mg, 0.5 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (98 mg, O.S5 mmol), and 4-methylmorpholine (0.066 mL, 0.6 mmol) in DMF (3 mL) was stirred at room temperature for 2 hours. Dimethyl L-glllt~m~te hydrochloride (0.116 g, 0.55 mmol) and 4-methylmorpholine (0.066 mL, 0.6 mmol) were sequentially added and the mixture was stirred overnight at room temperature.
The solvent was removed i~1 vacuo, and the residue chromatographed using chloroform:methanol (9:1) to give dimethyl N-~4-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-2-ylcarbonyl}-L-~lut~m~te (152 mg, 66%) as a white solid, mp 151-153~C: IH N~ (CDCI3/1 drop CD30D) ~ 10.20 (br s, 1 H), 7.27 (s, 1 H, J = 7.9 Hz), 6.70 (s, 1 H), 6.82 (s, 1 H), 5.83 (br s, 2 H), 5.38 (br s, 1 H), 4.80 (m, 1 H), 3.84 (s, 3 H), 3.73 (s, 3 H), 3.42 (br d, 1 H, J = 10.1 Hz), 3.05 (m, l H), 2.76 (dd, 1 H, J = 15.0, 4.4 Hz), 2.65 (m, 2 ~I), 2.56 (m, 2 H), 2.36 (m, 1 H), 2.14 (m, 2 H), 1.91 (m, 1 H), 1.68 (m, 2 H).
for C21H28N6O6 l.5H2O: C, 53.71; H, 6.23; N, 17 91 Found: C
53.34; H, 6.12; N, 18.03.

Dimethyl N-{5-12-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d}-pyrimidin-6-yl)ethylJpyrrol-2-ylcarbonyl}-~glutamate - Similarly obtained from 5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido-[2,3-d]pyrimidin-6-yl)ethyl]pyrrole-2-carboxylic acid (227.5 mg g, 0.75 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (145 mg, 0.825 mmol), 4-methylmorpholine (0.20 mL, 1.8 mmol), and dimethyl L-glutamate hydrochloride (191 mg, 0.9 mmol) CA 022',1813 1998-10-13 W 097/41115 PCTrUS96/14822 according to the method of Example lS is dimethyl N-{5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-2-ylcarbonyl}-~-glut~m~te as a pale yellow solid after flash column chrol--atography using chloloro~ methanol (4:1). The analytical sample, mp 200-202~C, was recryst~lli7ed from methanol: IH5NMR (CD30D) o 6.85 (d, 1 H, J ~ 3.7 Hz), 6.03 (d, 1 H, J = 3.7 Hz), 4.69 (m, 1 H), 3.81 (s, 3 H), 3.72 (s, 3 H), 3.40 (m, 1 H), 3.02 (m, I ~), 2.87 - 2.60 (m, 3 H), 2.56 (m, 2 H), 2.34 (m, 1 H), 2.40 - 2.07 (m, 2 H), 1.84 (m, 1 H), 1.77(m, 2 H). Anal.
Calcd for C21H29N6O60.5 H2O: C, 53.71; H, 6.23; N, 17.91. Found: C, 53.48; H, 6.08;N, 18.02.

Dimethyl N-{5-[2-(Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-dlpyrimidin-~yl)ethyl] pyrrol-3-ylcarbonyl}-I~glutamate From 5-~2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)-15ethyl]pyrrole-3-carboxylic acid (228 mg, 0.75 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (145 mg, 0.825 mmol), 4-methylmorpholine (0.20 mL, 1.8 mmol), and dimethyl L-glutamate hydrochloride (191 mg, 0.9 mmol) there is obtained according to the procedure of Example 15, dimethyl N-{5-[2-(amino-4-hydroxy-5,6,7,8-tetrahydro-pyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-3-ylcarbonyl}-L-glutamate as a white solid 20(184 mg, 53%) after flash column chromatography (chlorofo~ methanol, 4:1): ~H
NMR (CD30D) ~ 7.25 (d, 1 H, J = 1.7 Hz), 6.30 (d, 1 H, J = 1.7 Hz), 4.58 (m, 1 H), 3.71 (s, 3 H), 3.63 (s, 3 H), 3.33 (m, 1 H), 2.92 (dd, 1 H, J = 12.2, 8.5 Hz), 2.71 -2.60 (m, 3 H), 2.45 (t, 2 H, J = 7.3 Hz), 2.22 (m, 1 H), 2.09 - 1.96 (m, 2 H), 1.76 (m, 1 H), 1.66 (m, 2 H).
25Anal. Calcd for C21H28N6O6 1.5 H2O: C, 51.74; H, 6.41; N, 17.24. Found: C, 51.57; H, 6.58; N, 16.90.

Dimethyl N-{5-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d]-30pyrim id in-6-yl)ethyl] pyrazol-3-ylcarbonyl} -~glutamate From 5-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)eth-yl]pyrazole-3-carboxylic acid (228 mg g, 0.75 mmol), 2-chloro-4,6-dimethoxy-1,3,5-triazine (145 mg, 0.825 mmol), 4-methylmorpholine (0.20 mL, 1.8 rnmol), and dimethyl L-glut~m~te hydrochloride (191 mg, 0.9 mmol), there is obtained according to the procedure of Example IS, dimethyl N-{5-[2-(2-amino-4-hydroxy-5,6,7,8-CA 022~1813 1998-10-13 W O97/41115 rCT~US96/14822 tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrazol-3-ylcarbonyl}-L-ghlt~m~te (175 mg, 51%, mp 219-221~C); IH NMR (CDC13/CD30D, 3/1) ~ 6.55 (s, I H), 4.62 (m, lH),3.77(s,3H),3.54(s,3H),3.18(brd,1H,J=11.6Hz),2.79(m,1H),2.61(m, 2H), 2.43 (brd, 1 H, J = 15.0 Hz), 2.37 (t, 2H, J = 4.3Hz), 2.18 (m, 1 H), 2.03 (m, S 1 H), 1.78 (dd, 1 H, J = 15.0 Hz), 1.63 -1.35 (m, 3 H). HR FAB MS calcd for C20H28N7O6 462.2101 (M++H), found 462.2094.

N-{4-[2-(Amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d3pyrimidin-6-yl)ethyll pyrrol-2-ylcarbonyl} -~glutam ic Acid A solution of dimethyl N-{4-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido-[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-2-ylcarbony}-L-gll-t~m~te (92 mg, 0.2 mmol) in lN
sodium hydroxide ( 1 mL) was stirred at room temperature for 3 days, then acidified to pH 5 by addition of glacial acetic acid. The white solid was collected by filtration, washed with water, and dried in vacuo to give N-{4-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-2-ylcarbonyl}-L-glutamic acid (68 mg, 79%) as a white solid: IH NMR (DMSO-d6) o 11.44 (s, 1 H), 9.84 (br s, 1 H), 7.79(d, lH,J=7.7Hz),6.64(s,2H),6.23(s, lH),5.97(s,2H),4.27(s, lH),3.16 (brd, 1 H, J = 9.6Hz), 2.74 (brt, 1 H, J = 10.2Hz), 2.45 - 2.18 (m, 5 H), 1.95 - 1.75 (m 3 H) 1 65 - 1 40 (m, 3 H). HR FA~ MS calcd for ClgH25N6O6 433.1836 (M~+H), found 433.1866.
Anal. Calcd for ClgH24N606 1.5H20 C, 49.65; H, 5.93; N, 18.30. Found: C, 49.28; H, 5.89; N, 18.38.

N-{5-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-dlpyrimidin-~
yl)ethyl]pyrrol-2-ylcarbonyl}-L~glutamic Acid Similarly prepared from dimethyl N-{5-[2-(2-Amino-4-hydroxy-5,6,7,8-tetra-hydropyrido[2,3-d]pyrimidin-6-yl)ethyl]pyrrol-2-yl]carbonyl3-L-~hlt~m~te (138 mg g, 30 0.3 mmol) and lN sodium hydroxide (1.5 mL) according to the procedure of Example 19 is N-{5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido~2,3-d]pyrimidin-6-yl)eth-yl]pyrrol-2-ylcarbonyl}-L-glutamic acid as an off white solid (105 mg, 81%), mp ~260~C: 'H NMR (DMSO-d6) ~ 11.22 (s, I H), 9.76 (br s, 1 H), 7.83 (d, 1 H, J = 7.8 Hz), 6.69 (s, 1 H), 6.27 (s, 1 H), 5.g7 (s, 2 H), 5.81 (s, 1 H), 4.32 (s, 1 H), 3.16 (m, 1 H), 2.73 (m, 1 H), 2.61 - 2.24 (m, 3 H), 2.28 (m, 2 H), 2.02 - 1.69 (m, 3 H), 1.60 -W O 97/41115 PCT~US96/14822 1.43 (m, 3 H). HR FAB MS calcd for ClgH25N606 433.1836 (M++H), found 433.1840.
Anal Calcd for C19H24N6O60.5 H2O: C, 51.70; H, 5.71; N, 1904 Found C
51.79; H, 5.90; N, 18.87.
EXAA~PLE 21 N-{5-[2-(A mino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d]pyrimi~i~ 6 yl)ethyl~pyrrol-3-~lcarbonyl}-L,glutamic Acid From dimethyl N-{5-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyridor2,3-d]-pyrimidin-6-yl)ethyl]pyrrol-3-ylcarbonyl}-L-~ t~ te (92 mg g, 0.2 mmol) and IN
sodium hydroxide (1 mL), there is similarly obtained according to the procedure of Example 19 N-~5-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido~2,3-d]pyrimidin-6-yl)ethyl]pyrrol-3-ylcarbonyl}-L-glutamic acid as an off-white solid (57 mg, 66%, mp >260~C~: 'H NMR (CD30D) ~ 7.25 (d, 1 H, J = 1.6 Hz), 6.30 (d, I H, J = 1.6 Hz), 1~ 4.53 (m, 1 H), 3.33 (m, 1 H), 2.92 (dd, 1 H, J = 12.2, 8.5 Hz), 2.70 - 2,60 (m, 3 H), 2.43 (t, 2 H, J = 7.6 Hz), 2.22 (m, 1 H), 2.08-1.96 (m, 2 H), 1.76 (m, 1 H), 1.66 (m, 2 H). HR FAB MS calcd for ClgH25N606 433.1836(M~+H), found 433.l858.
Anal. Calcd fior ClgH24N6O6H2O C, 50 66; H, 5.82; N, 18.66 ~ound C
50.58; H, 5.58; N, 18.37.
EX,4MPLE 22 N-{~-12-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-d]pyrimidin-6-yl)ethyl]pyrazol-3-ylcarbonyl}-L,glutamic Acid From dimethyl N-{5-~2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyri-midin-6-yl)ethyl]pyrazol-3-ylcarbonyl}-L-pI-lt~m~te (92 mg, 0.2 mmol) and IN sodium hydroxide (0.5 mL), there is similarly obtained according to the procedure of Example 19, N-{5-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido~2,3-d]pyrimidin-6-yl)ethyl]-pyrazol-3-ylcarbonyl}-L-glutamic acid (69 mg, 79%, mp ~260~C): IH N~ (DMSO-d6) ~ 12.90 (br s, I H), 9.84 (br s, 1 H), 7.99 (d, 1 H, J = 7.7 Hz), 6.43 (s, 1 H), 6.26 (s, lH),5.98(s,2H),4.24(m, lH),3.16(brd, lH,J=10.4Hz),2.77(m, lH),2.67 (m, 2 H), 2.47 (brd, 1 H, J - 15.0 Hz), 2.26 (m, 2 H), 2.05-1.74 (m, 3 H), 1.68 -1.45 ~m, 3 H). HR FAB MS calcd for C 18H24N7O6 434.1788 (Mt+H), found 434.1813.

CA 0225l8l3 l998-l0-l3 W 0 97/41115 PCTrUS96/14822 Dimethyl N-{2-12-(2-Pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)etl~ l]-l-triphenylm~lhylil,-idazol-4-ylcarbonyl}-I~glutamate Following the procedure of Example 1, dimethyl N-(2-iodo-1-triphenylmethylimi-dazol-4-ylcarbonyl)-L-glllt~m~te (638 mg, 1.0 mmol), 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine (541 mg, 2.0 mmol), Pd(PPh)2C12 (35 mg, 0.05 mmol), cuprous iodide (19 mg, 0.1 mmol), triethylamine (0.7 mL), and acetonitrile (50 mL) yield dimethyl N-{2-[2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)ethynyl]-1-triphenylmethylimid~7.01-4-ylcarbonyl}-L-glutamate [515 mg, 66% after flash column chromatography (ethyl acetate:hexanes, 2:1), mp 93-95~C]: IH Nl~
(CDC13) o 12.05 (br s, 1 H), 8.43 (br s, 1 H), 8.26 (s, I H), 7.93 (d, 1 H, J = 2.2Hz), 7.61 (s, 1 H), 7.54 (d, 1 H, J = 7.6 Hz), 7.33 - 7.28 (m, 9 H), 7.18 - 7.12 (m, 6 H), 4.77 (m, I H), 3.74 (s, 3 H), 3.65 (s, 3 H), 2.45 (m, 2 H), 2.32 (m, 1 H), 2.05 (m, 1 H), 1.30 (s, 9 H). ~MS calcd for C44H41N707 779.3067, found 779.3088.
Anal. Calcd for C44H41N707: C, 67.77; H, 5.30; N, 12.57. Found: C, 67.48; H, 5.59; N, 22.72.
The starting material can be prel)aled in the following manner. A mixture of 2-iodo-4-hydroxymethyl-1-(triphenylmethyl)imid~7.01e (3.264 g, 7.0 mmol) and m~ng~nese dioxide (12.17 g, 140 mmol) in methylene chloride (100 mL) was stirredovernight at room te"~pe~alu~e and filtered though Celite. The filtrate was concentrated in vacuo to give 2-iodo-4-formyl-1-triphenylmethylimidazole as a white foamy solid (3.05 g, 94%), mp 173-75~C which was sufficiently pure to be used in the next step without further purification. ~H NMR (CDCl3) ~ 9.77 (s, 1 H), 7.55 (s,1 H), 7.38-7.30 (m, 9 H), 7.16-7.09 (m, 6 H).
Anal. Calcd for C23H17IN2O: C, 59.50; H, 3.69; N, 6.03. Found: C, 59.27; H, 3.76; N, 5.95.
To a mixture of activated m~ng~nese dioxide (5.66 g, 65 mmol), sodium cyanide (833 mg, 17 mmol), and glacial acetic acid (300 mg) in meth~nol (70 mL) was added 2-iodo-4-formyl-1-triphenylmethylimidazole (2.33 g, 5.0 mmol) in one portion. The mixture was stirred for 1 hour at room temperature and then filtered through Celite.
The filtrate was concentrated and the residue was partitioned into methylene chloride and water. The organic phase was dried (magnesium sulfate) and concentrated in vacuo to give a white foamy solid. Purification by column chrol"alography using ethyl acetate:hexanes (1 :2) afforded 2-iodo-4-(methoxycarbonyl)-1-triphenylmethylimid-CA 022~1813 1998-10-13 W O 97/41115 PCTrUS96/14822 azole (2.26 g7 92%) as a white solid, mp 192-194~C ~H NMR (CDC13) ~ 7.55 (s, 1 H), 7.37-7.29 (m, 9 H), 7.18-7.09 (m, 6 H), 3.84 (s, 3 H).
Anal. Calcd for C24H19IN2O2: C, 58.31; H, 3.87; N, 5.67. Found: C, 58.03; H, 3.90; N, 5.64.
A suspension of 2-iodo-4-(methoxycarbonyl)-1-triphenylmethylimidazole (1.978 g, 4 mmol) in 6N sodium hydroxide (15 mL) was heated at reflux for 4 hours. The resulting suspension was diluted with ethyl acetate (20 mL) and then slightly acidified with acetic acid. The resulting clear solution was extracted three times with ethyl acetate (20 mL) and the combined extracts were dried (magnesium sulfate) and concentrated in vacuo. Residual acetic acid was removed under high vacuum to give 2-iodo-1-triphenylmethylimidazole-4-carboxylic acid (1.67 g, 87%) as a white solid, mp 203-205~C: lH NMR (CDC13) ~ 7.60 (s, 1 H), 7.38 - 7.20 (m, 9 H), 7.18 - 7.09 (m, 6 H).
Anal Calcd for C23H17IN2O2: C, 57.52; H, 3 57; N, 5 83 Found C, 57 37; H~
3.87; N, 5.65.
2-Iodo-1-triphenylmethylimidazole-4-carboxylic acid (1.443 g, 3.0 mmol), 2 chloro-4,6-dimethoxy-1,3,5-triazine (553 mg, 3.15 mmol), 4-methylmorpholine (0.614 mL, 6.6 mmol), dimethyl L-gll~t~m~te hydrochloride (698 mg, 3.3 mmol), and tetrahydrofuran (20 rnL) were then allowed to react in the manner described in Example 15 to yield dimethyl N-(2-iodo-1-triphenylmethylimidazol-4-ylcarbonyl)-L-glllt~m~te (1.44 g, 75%, mp 86-88~C): lH NMR (CDC13) ~ 7.47 (s, 1 H), 7.44 (d, 1 H, J = 8.6 Hz), 7.32 - 7.26 (m, 9 H), 7.21 - 7.05 (m, 6 H), 4.72 (m, 1 H), 3.71 (s, 3 H), 3.62 (s, 3 H), 2.41 (m, 2 H), 2.27 (m, 1 H), 1,99 (m, 1 H). HRMS calcd forC30H28IN305 637.1074, found 637.1054. Anal. Calcd for C30H28IN305: C, 56.52 H, 4.43; N, 6.59. Found: C, 56.36; H, 4.45, N, 6.57.

Dimethyl N-{2-12-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,~
d]pyrimidin-6-yl)ethyl]imidazol-4-ylcarbonyl}-~glutamate A mixture of dimethyl N-{2-~2-(2-pivaloylamino-4-hydroxypyrido[2,3-d]-pyrimidin-6-yl)ethynyl] - 1 -triphenylmethylimidazol-4-ylcarbonyl ~ -L-glutamate (390 mg, 0.5 mmol) and 10% palladium-on-carbon catalyst (390 mg) in methanol (15 mL) was stirred under 50 psi of hydrogen for 7 days at room temperature. The workup was performed as described in Example 2 to yield 130 mg (48%) of dimethyl N-{2-[2 (2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]imid-CA 022~1813 1998-10-13 azol-4-ylcarbonyl}-L-gl~1t~m~te as a pale yellow solid, mp 129-131~C: 'H NMR
(CDCl3) ~ 11.35 (br s, 1 H), 8.95 (br s, 1 H), 7.54 (d, I H, J = 8.4 Hz), 7.49 (s, 1 H), 4.75 (m, 1 H), 3.69 (s, 3 H), 3.60 (s, 3 H), 3.30 (M, 1 H), 2.87 (m, 1 H), 2.80 - 2.60 (m,3H),2.43(m,2H),2.27(m, lH),2.15-1.92(m,2H), 1.~0- 1.60(m,3H), 1.26 5 (s, 9H) N-{2-[2-(Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3dlpyrimidin-~
yl)ethyl]imidazol-4-ylcarbonyl}-I~glutamic Acid Dimethyl N-{2-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d~-pyrimidin-6-yl)ethyl]imidazol-4-ylcarbonyl}-L-glut~m~te (109 mg g, 0.2 mmol) and0.5N sodium hydroxide (1 mL) are allowed to react analogously to the method described in Example 19 to yield N-~2-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido-[2,3-d]pyrimidin-6-yl)ethyl]imidazol-4-ylcarbonyl}-L-glutamic acid (38 mg, 44%, mp ~260~C): lH NMR (DMSOd6) d 12.35 (br s, 1 H), 12.21 (br s, 1 H), 9.77 (br s, 1 H), 7.80 (br s, 1 H), 7.50 (s, 1 H), 6.27 (s, 1 H~, 5.92 (s, 2 H), 4.37 (m, 1 H), 3.17 (br d, 1 H, J = 10.6 Hz), 2.79-2.61 (m, 3 H), 2.44 (m, 1 H), 2.26 (m, 2 H), 2.07-1.76 (m, 3 H), 1.68 - 1 .59 (m, 3 H).

Diethyl N-{2-12-Pivaloylamino-4-hydroa~)yr:do[2,3--flpyrimidin-6-ylethynyl] -4-thiazolylcarbonyl} -L-glutamate To a 100 mL 14/20 round bottom flask under an argon atmosphere were added 0.316 g (1.17 mmol) of 2-pivaloylamino-4-hydroxy-6-ethynylpyrido~2,3-d~pyrimidine suspended in 10 mL of acetonitrile, followed by the addition of 0.47 g (1.2 mmol) of diethyl N- (2-bromo-4-thiazolylcarbonyl)-L-glutamate, 0.14 g (0.12 mmol) of tetrakis(triphenylphosphine)palladium (0), 0.046 g (0.24 mmol) of copper (I) iodide, and 0.35 mL (2.5 mmol) oftriethylamine with an additional 10 mL of acetonitrile. The reaction was heated to reflux for 2 hours The volatiles were removed in vacuo, and the residue purified using silica gel flash chromatography, eluting with a step gradient of 100% chloroform to 2% methanol/chloroform to give 0.46 g (67%) of diethyl N-{2-[2-pivaloylamino-4-hydroxypyrido[2,3-d~pyrimidin-6-ylethynyl]-4-thiazolylcarbonyl} -L-glutamate as an off-white solid, m.p. 201-202~ C (dec). Rf = 0.28 (4%
methanol/chloroform). lH NMR (300 MHz, DMSO- d6) o 1.12-1.29 (m, 15 H), 2.05-CA 022~1813 1998-10-13 2.15 (m, IH), 2.37 (t, J = 7.2 Hz, 2H), 3.98-4.13 (m, 4H), 4.45-4.49 (m, lH), 8.47 (s, lH), 8.61 (d, J = 1.8 Hz, lH), 8.84 (d, J= 8.1 Hz, lH), 9.07 (d, J = 1.9 Hz, lH) The starting material can be prepared as follows.
To a 100 rnL 24/40 round bottom flask was charged 3.25 g (13.8 mmol) of 2-bromo-4-thiazolecarboxylic acid ethyl ester (Heh~. Chim. Acta, 1942, 25, 1073) dissolved in 20 mL of lN sodium hydroxide. The reaction was stirred at room temperature for 3 h, cooled down in an ice bath and acidified to pH 2 with SN
hydrochloric acid. The white precil)ila~e was filtered, washed with 20 mL cold water, and dried in a vacuum oven to give 2.7 g (94%) of 2-bromo-4-thiazolecarboxylic acid.
10 m.p. 227-229O C, Rf = 0.16 (20% methanoVchloroform). lH NMR (300 MHz, DMSO- d6) ~ 8.43 (s, lH).
Anal. Cal'd for C4H2BrNO5S: C, 23.10; H, 0.97; N, 6.73. Found: C, 23.42; H, 0.97; N, 6.51.
To a 100 mL 14/20 round bottom flask under a nitrogen atmosphere was charged 1.7 g (8.17 mmmol) of 2-bromo-4-thiazolecarboxylic acid in 17 mL of benzene, followed by the addition of 2.4 mL (33 rnmol) of thionyl chloride, and a catalytic amount of dimethylro~ -llide. The reaction was heated to reflux for 2 hours The volatiles were removed in vacuo, and this residue was then dissolved in 20 mL ofmethylene chloride and added dropwise to an ice-bath cooled mixture of 2.06 g (8.58 20 mmol) of L-glutamic acid diethyl ester, 2.39 mL (10.1 mmol) oftriethylamine, and 10 mg of dimethylaminopyridine in 30 mL of methylene chloride. A~er the addition, the ice bath was removed and the reaction was stirred at room temperature for 2 hours The reaction was diluted with methylene chloride, washed with 0.5 N hydrochloricacid, water, 5% sodium bicarbonate, water, dried over sodium sulfate, and removed in vacuo. The crude residue was purified using silica gel flash chromatography eluting with 3: 1 chloroform/ether to give 2.7 g (84%) of diethyl N- (2-bromo-4 thiazolylcarbonyl)-L-ghlt~m~te as a yellow oil. Rf= 0.43 (3:1chloroform/ether). lH
NMR (300 MHz, DMSO- d6) o 1.14 (q, J = 7.1 Hz, 6 H), 1.98-2.18 (m, 2H), 2.35 (t,J = 7.3 Hz, 2H), 3.97-4.11 (m, 4H), 4.37-4.50 (m, lH), 8.28 (d, J = 5.9 Hz, lH), 8.73 (d, J= 7.7 Hz, lH) Anal. Cal'd for C13Hl7BrN2O5S: C, 39.71; H, 4.36; N, 7.12. Found: C, 39.84 H, 4.29; N, 7.36.

CA 022~1813 1998-10-13 Diethyl N-{2-12-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydro-pyridol2,3-dl pyrimidin-6-yl)ethyll-4-thiazo~ylcarbonyl~-L,glutamate To a 50 mL round bottom flask were charged 0.25 g (0.43 mmol) of diethyl N-t2-[2-pivaloylamino-4-hydroxypyrido[2,3-d~pyrimidin-6-ylethynyl]-4-thiazolylcarbonyl}-L-glllt~m~te dissolved in 8 mL of glacial acetic acid, followed by the addition of 0.25 g of platinum oxide catalyst. The reaction was then stirred under hydrogen at 1 atmosphere for 24 hours The catalyst was then filtered away, and the filtrate was 10 removed in vacuo. The residue was then purified using silica gel flash cluo.natography eluting with 2% methanol/chloroform to give 0.092 g (36%) of diethyl N-{2-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d~pyrimidin-6-yl)ethyl]-4-thiazolylcarbonyl} -L-glutamate, m.p. 63-166O C, as a yellow solid. Rf= 0.28 (5%
meth~noVchloroform); lH NMR (300 MHz, DMSO d6) ~ 1.09-1.23 (m, 15 H), 1.73-1.77 (m, 3H), 1.97-2.10 (m, 4H), 2.34 (t, J = 7.2 Hz, 2H), 2.50-2.62 (m, 2H), 2.86-2.95 (m, lH), 3.08-3.12 (m, 2H), 3.96-4.11 (m, 4H), 4.43-4.45 (m, lH), 6.46 (s, lH), 8.14 (s, lH), 8.48 (d, J = 8.0 Hz, lH) N-{2-12-(2-Amino-4-hydroxy-5,6,7,8-tetrahyd~ r ~o[2,3-dlpyrimidin-6-yl)ethyl]-4-thiazolylcarbonyl}-L~glutamic Acid To a 25 mL 14/20 round bottom flask was charged 0.067 g (0.11 mmol) of diethyl N-{2-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydl opylido[2,3-dlpyrimidin-6-yl)ethyl]-4-thiazolylcarbonyl}-L-~ t~m~te dissolved in 3 mL of lN sodium hydroxide.
The reaction was stirred at room temperature for 84 hours The solution was cooled down in an ice bath and acidified with lN hydrochloric acid to pH 3. The pre~;ipiLate was filtered, washed with 25 mL water, and dried in a vacuum oven at 60O C to give 0.036 g (70%) of N-t2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d~pyrimidin-6-yl)ethyl]-4-thiazolylcarbonyl~-L-glutarnic acid m.p. 210-212O C as a tan solid. Rf = 0.08 (50% methanol/chloroform); lH NMR (300 MHz, DMSO d6) o 1.69-2.09 (m, 8H), 2.26 (t, J = 7.1 Hz, 2H), 2.80 (t, J = 8.2 Hz, 2H), 3.05-3.17 (m, 2H), 4.34-4.41 (m, lH), 5.93 (s, 2H), 6.26 (s, lH), 8.12 (s, lH), 8.33 (d, J = 7.7 Hz, lH), 9.70(brs, lH).

CA 022~1813 1998-10-13 Diethyl N-{2-[2-Pivaloylamino-4-hydroxypyridol2,3-dlpyrirli-l 6 yl-etl~ l]-~-thiazolylcarbonyl}-L~glutamate In a similar fashion to that described in Example 26, there is obtained from 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d~pyrimidine (0.57 mmol) and of N-(2-bromo-5-thiazolylcarbonyl)-L-glutamic acid diethyl ester (0.58 mmol), 0.19 g ~56%) of diethyl N-{2-[2-pivaloylamino-4-hydroxypyrido~2,3-d~pyrimidin-6-ylethynyl]-5-thia-zolylcarbonyl}-L-glllt~m~te as an off-white solid m.p. 223-225O C (dec). Rf= 0.25 10 (5% methanoUchloroform). lH NMR (300 MHz, DMSO d6) o 1.17 (q, J = 7.5 Hz, 6H), 1.25 (s, lH), 1.95-2.11 (m, 2H), 2.42-2.48 (m, 2H), 3.99-4.14 (m, 4H), 4.38-445 (m, lH), 8.29 (s, lH), 8.63 (d, J - 2.1 Hz, lH), 9.08 (d, J = 2.0 Hz, lH), 9.12 (d, J =
7.4 Hz, lH).
Anal. Cal'd for C27H30N6O6S: C, 55.66; H, 5.19; N, 14.42. Found: C, 55.95;
15 H, 5.16; N, 14.57.
The starting material can be prepared as follows: To a 500 mL 24/40 3-neck round bottom flask equiped with a mechanical stirrer, was charged 3.4 g (19.7 mmol) of 2-amino-5-thiazolecarboxylic acid ethyl ester (Ber., 1888, 21, 938), partially dissolved in 30 mL of concentrated phosphoric acid. The stirring mixture was cooled in an ice bath and then 9 mL of concentrated nitric acid was added slowly, followed by the dropwise addition of 2.85 g (41.3 mmol) of sodium nitrite in 5 mL of water. The mixture was stirred in the cold for 35 mimltes, and then added dropwise was 3.0 g (47.2 mmol) of copper powder in 75 mL of 48% hydrobromic acid cooled to -lOo C.
After the evolution of nitrogen gas ceased, the thick reaction mixture was removed from the ice bath and neutralized to pH 8, first using SN sodium hydroxide and then sodium carbonate. The aqueous was then extracted with 400 mL ether. The insoluble material was filtered away and the filtrate was washed with 5% sodium bicarbonate, water, dried over sodium sulfate, and removed in vacuo. The crude residue was then purified using silica gel flash chromatography eluting with 1:1 ether/hexanes to give 2.4 g (52%) of 2-bromo-5-thiazolecarboxylic acid ethyl ester as a yellow oil. Rf= 0.62 (1:1 ether/hexanes). lH NMR (300 MHz, DMSO d6) o 1.26 (t, J = 7.0 Hz, 3H), 4.29 (q, J = 7.1 Hz, 2H), 8.28 (s, lH).
Anal. Cal'd for C6H6BrNO2S: C, 30.53; H, 2.56; N, 5.93. Found: C, 30.78; H, 2.62; N, 5.98.

CA 022~1813 1998-10-13 W O 97/41115 PCT~US96/14822 To a 100 mL 14/20 round bottom flask was charged 2.4 g (10.1 mmol) of 2-bromo-5-thiazolecarboxylic acid ethyl ester dissolved in 14 mL of lN sodium hydroxide. The reaction was stirred at room temperature for 1.5 hours The yellowsolution was acidified with SN hydrochloric acid to pH 2. The solid which formed was S cooled in an ice bath, filtered, washed with water, and dried in a vacuum oven at 60O C
to give 1.9 g (90%) of 2-bromo-5-thiazolecarboxylic acid m.p. 185-186O C (dec) as a white solid. Rf= 0.12 (20% methanol/chloroform). lH NMR (300 MHz, DMSO d6) ~8.19(s, lH).
To a 100 mL 14/20 round bottom flask under a nitrogen atmosphere was charged 1.0 g (4.81 mmmol) of 2-bromo-4-thiazolecarboxylic acid in 10 mL of benzene, followed by the addition of 1.4 mL (19 mmol) of thionyl chloride, and a catalytic amount of dimethylformamide. The reaction was heated to reflux for 2 hours The volatiles were removed in vacuo, and this residue was then dissolved in 15 mL ofmethylene chloride and added dropwise to an ice-bath cooled mixture of 1.21 g (S.OS
mmol) of L-glutamic acid diethyl ester, 1.41 mL (10.1 mmol) oftriethylamine, and 5 mg of dimethylaminopyridine in l S mL methylene chloride. A~[er the addition, the ice bath was removed and the reaction was stirred at room temperature for 2 hours The reaction was diluted with methylene chloride, washed with 0.1 N hydrochloric acid, water, 5% sodium bicarbonate, water, dried over sodium sulfate, and removed in vacuo. The crude residue was purified using silica gel flash chromatography eluting with a gradient of 1 :2 ethyl acetate/hexanes to 1: 1 ethyl acetate/hexanes to give 0.9 g (48%) of N-[(2-bromo-5-thiazolyl)carbonyl]-L-glutamic acid diethyl ester as a yellow oil. Rf= 0.30 (1:2 ethyl acetate/hexanes); lH NMR (300 MHz, CDC13) o 1.24-1.34 (m, 6H), 2.15-2.32 (m, 2H), 2.47-2.55 (m, 2H), 4.12-4.30 (m, 4H), 4.64-4.71 (m, lH), 7.97 (s, lH) Diethyl N-{2-[2-(2-Pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido-[2,3-~flpyrimidin-6-yl)ethyl]-5-thiazolylcarbonyl}-~glutamate In a similar fashion to that described in Example 27, there is obtained from diethyl N-{2-[2-pivaloylamino-4-hydroxypyrido[2,3-dlpyrimidin-6-ylethynyl]-S-thiazolylcarbonyl}-L-glut~m~te, diethyl N-{2-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-c~pyrimidin-6-yl)ethyl]-S-thiazolylcarbonyl}-L-glut~m~te as a yellow solid, m.p. 156-159o C; Rf= 0.36 (10% methanol/chloroform); lH NMR (300 MHz, DMSO-d6) ~ 1.11-1.23 (m, 15H), 1.66-1.76 (m, 3H), 1.89-2.08 (m, 3H), 2.40 CA 022~1813 1998-10-13 W O 97/41115 PCTrUS96/14822 (t, J = 7.4 Hz, 2H), 2.51-2.55 (m, lH), 2.85-2.89 (m, lH), 3.06 (t, J = 6.6 Hz, 1H), 3.14 (d, J = 5.2 Hz, 2H), 3.98-4.11 (m, 4H), 4.33-4.37 (m, lH), 6.45 (s, lH), 8.30 (s, lH), 8.84 (d, J = 7.4 Hz, lH).

N-~2-[2-(2-Amino-4-hydroxy-5,6,7,8-tetrahydropyridol2,3-dlpyrimidin-6-yl)ethyl]-5-thiazolylcarbonyl}-I~glutamic Acid In a similar fashion to that described in Example 28, there is obtained from diethyl N-{2-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d~pyrimidin-6-yl)ethyl]-5-thiazolylcarbonyl}-L-glutamate, N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetra-hydropyrido[2,3-a!lpyrimidin-6-yl)ethyl]-5-thiazolylcarbonyl}-L-glutamic acid, as a pale yellow solid, m.p. 197-199o C (dec); Rf= 0.09 (50% methanoVchloroform); lH
NMR (300 MHz, DMSO d6) ~ 1.67-1.92 (m, 6H), 2.03-2.08 (m, 2H), 2.33 (t, J = 7.0 Hz, 2H), 2.79-2.82 (m, lH), 3.10-3.21 (m, 2H), 4.33-4.40 (m, lH), 5.95 (s, 2H), 6.28 (s, lH), 8.31 (s, lH), 8.75 (d, J = 7.7 Hz, lH), 9.75 (br s, lH) Hard gelatin capsules are prepared using the following ingredients:
Quantity (mglcapsule) N- { 3 -~2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido 2,3-d]pyrimidin-6-yl)ethyl]- 250 pyrazol-5-ylcarbonyl ~ -L-glutamic acid Starch, dried 200 Magnesium stearate 10 460 mg CA 022~1813 1998-10-13 W O 97/41115 PCT~US96/14822 Tablets are prepared using the ingredients below:
Quantity S (m~/capsule) N- { 2-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido-[2,3-d]pyrimidin-6-yl)ethyl]- 250 imidazol-4-ylcarbonyl}-L-glutamic acid Cellulose, microcrystalline 400 Silicon dioxide, fumed 10 Stearic acid 5 665 mg The components are blended and co,n~ ssed to form tablets each weighing 665 mg.

EX,4MPLE 34 An intravenous formulation may be prepared as follows:
Ouantity N- {4-[2-(amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidin-6-yl)ethyl]pyrrol-2-ylcarbonyl}-L-glutamic acid 100 mg Isotonic saline 1,000mL
The following examples illustrate specific aspects of the present invention and are not intended to limit the scope thereof in any respect and should not be so construed.

Claims (15)

What is claimed is:

1. A compound selected from the group consisting of (i) a fused pyrimidine of the formula:

in which R1 is -OH or -NH2, R2 is -OH or an a carboxylic acid protecting group, R3 is -H or an amino protecting group, Z is a divalent, five-membered, nitrogen-containing heterocyclic ring system optionally containing a sulfur or nitrogen atom as a second hetero ring member, said valence bonds originating from nonadjacent carbon atoms of said ring, n has a value of 2 or 3, and the configuration about the carbon atom designated * is L, and (ii) a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 in which Z is pyrrolediyl.

3. A compound according to claim 1 in which Z is imidazolediyl.

4. A compound according to claim 1 in which Z is pyrazolediyl.

5. A compound according to claim 1 in which Z is thiazolediyl.

6. A compound according to claim 1 in which in said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine R1 is -OH, R2 is -OH, R3 is -H, and n has a value of 2.

7. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine isN-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-5-ylcarbonyl}-L-glutamic acid.

8. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-4-ylcarbonyl}-L-glutamic acid.

9. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrrol-2-ylcarbonyl}-L-glutamic acid.

10. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{3-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-pyrazol-5-ylcarbonyl}-L-glutamic acid.

11. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-4-ylcarbonyl}-L-glutamic acid.

12. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-thiazol-5-ylcarbonyl}-L-glutamic acid.

13. A compound according to claim 6 in which said 5,6,7,8-tetrahydropyrido[2,3-d]-pyrimidine is N-{2-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]-imidazol-4-ylcarbonyl}-L-glutamic acid.

14. The method of inhibiting neoplastic growth in a mammal which growth is dependent on folic acid or a metabolic derivative of folic acid as a substrate, which comprises a.1ministering to the mammal in a single or multiple dose regimen an effective amount of a compound according to claim 1.

15. A pharmaceutical composition for inhibiting neoplastic growth in a mammal which growth is dependent on folic acid or a metabolic derivative of folic acid as a substrate, which comprises an amount of a compound according to claim 1 which upon administration to the mammal in a single or multiple does regimen is effective to inhibit said growth, in combination with a pharmaceutically acceptable carrier.