Patents Represented by Attorney Robert K. Bair
  • Patent number: 4109092
    Abstract: The process of reacting a PY-carboxamidine with .alpha.-chloroacrylonitrile in the presence of an acid-acceptor to produce 2-PY-4-pyrimidinamines where PY is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents. The products produced by the process are useful as anti-allergic agents per se and, also, are useful as intermediates in the preparation of other anti-allergic agents, namely, dialkyl N-(2-PY-4-pyrimidinyl)-aminomethylenemalonates and analogs, as well as N-(2-PY-4-pyrimidinyl)ureas.
    Type: Grant
    Filed: October 7, 1976
    Date of Patent: August 22, 1978
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4107315
    Abstract: Compounds useful as cardiotonic agents are 1-R-3-Q-5-PY-2(1H)-pyridinones (I) where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, Q is amino (preferred), lower-alkylamino, di-(lower-alkyl)amino or NHAc, Ac is lower-alkanoyl or lower-carbalkoxy, and PY is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents. The corresponding compounds where Q is nitro, carbamyl, cyano, halo or hydrogen are useful as intermediates and those where Q is hydrogen or cyano also are useful as cardiotonic agents. Said compounds are prepared: by reacting .alpha.-PY-.beta.-(R.sub.1 R.sub.2 N)acrolein (II) with malonamide to produce 1,2-dihydro-2-oxo-5-PY-nicotinamide (Ia) and reacting Ia with a reagent capable of converting carbamyl to amino to produce 3-amino-5-PY-2(1H)-pyridinone (Ib); by reacting II or .alpha.-PY-malonaldehyde (II') with .alpha.
    Type: Grant
    Filed: July 25, 1977
    Date of Patent: August 15, 1978
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Chester J. Opalka, Jr.
  • Patent number: 4107167
    Abstract: Process of reacting 3-PY-aniline (I) with lower-alkyl acetoacetate (II) and tri-(lower-alkyl) orthoformate (III) to produce lower-alkyl .alpha.-(3-PY-anilinomethylene)acetoacetate (IV), heating lower-alkyl .alpha.-(3-PY-anilinomethylene)acetoacetate (IV), to produce 3-acetyl-1,4-dihydro-4-oxo-7-PY-quinoline (V) which is tautomeric with 3-acetyl-4-hydroxy-7-PY-quinoline (VA), reacting V (or VA) with a lower-alkylating agent to produce 3-acetyl-1-(lower-alkyl)-1,4-dihydro-4-oxo-7-PY-quinoline (VI) and converting VI to 1-(lower-alkyl)-1,4-dihydro-4-oxo-7-PY-3-quinolinecarboxylic acid (VII), where PY is 4(or 3)-pyridyl or 4(or 3)-pyridyl having one or two lower-alkyl substituents. The compounds of formula VII are known antibacterial agents.
    Type: Grant
    Filed: September 15, 1977
    Date of Patent: August 15, 1978
    Assignee: Sterling Drug Inc.
    Inventors: Roman R. Lorenz, William H. Thielking
  • Patent number: 4104385
    Abstract: Compounds useful as schistosomicidal agents are cyclic alkylidenyl N-[6-(R.sub.3 R.sub.4 N)-4(or 5)-R.sub.5 -3-pyridazinyl]aminomethylenemalonates (I), where R.sub.3 R.sub.4 N is lower-tertiary-amino and R.sub.5 is hydrogen or lower-alkyl, are prepared by reacting 3-amino-6-(R.sub.3 R.sub.4 N)-4(or 5)-R.sub.5 -pyridazine (III) with cyclic alkylidenyl .alpha.-(lower-alkoxymethylene)malonate (IV) or by heating equimolar quantities of III, tri-(lower-alkyl) orthoformate and cyclic alkylidenyl malonate (V). Also shown is cyclic isopropylidenyl N-(6-methylamino-3-pyridazinyl)aminomethylenemalonate, a schistosomicidal agent, and its preparation. Also shown are schistosomicidal compositions comprising as active component a schistosomicidally effective cyclic alkylidenyl N-[6-(R.sub.3 R.sub.4 N)-4(or 5)-R.sub.
    Type: Grant
    Filed: June 10, 1977
    Date of Patent: August 1, 1978
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Chester J. Opalka, Jr.
  • Patent number: 4086233
    Abstract: Compounds useful as anti-allergic agents are 2-Q-4-[XZC=C(R)NH]-5-R.sub.1 -6-R.sub.2 -pyrimidines (I), where Q is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents or N-oxide thereof, R is hydrogen or lower-alkyl, R.sub.1 is hydrogen, lower-alkyl or cyano, R.sub.2 is hydrogen, lower-alkyl, hydroxy or halo, X and Z are the same or different and are each selected from lower-carbalkoxy, lower-alkanoyl, carbamyl and cyano, or ##STR1## is ##STR2## wherein R.sub.3 and R.sub.4 are each lower-alkyl, or X is hydrogen, are prepared by reacting 4-amino-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidine (II where Q' is amino) with R'O-C(R)=CXZ (III). Preparations of II are given. Also shown as intermediates and/or anti-allergic agents are 4-(AcNH)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (IV) and 4-(R.sub.5 R.sub.6 N)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (V) where Ac is lower-alkanoyl or lower-carbalkoxy, R.sub.5 is hydrogen, lower-alkyl or lower-hydroxyalkyl, and R.sub.
    Type: Grant
    Filed: February 3, 1977
    Date of Patent: April 25, 1978
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4075217
    Abstract: 3-(4- OR 3-Pyridinyl)-2-cyclohexen-1-ones (I) and their oxime derivatives are useful in preparing (3-aminophenyl)-pyridines, in turn, useful in preparing known antibacterial agents. Also shown is the preparation of I by starting with the reaction of methyl vinyl ketone with either 1-(pyridinyl)-1-(lower-tertiary-amino)-ethylene (II) or lower-alkyl 3-(pyridinyl)-3-oxopropanoate. Also shown is the process of converting I to its oxime, acylating the oxime and heating the acylated oxime under acidic conditions to produce N-(lower-acyl)-3-(pyridinyl)-aniline (VII), and hydrolyzing VII under aqueous alkaline conditions to produce the corresponding 3-(pyridinyl)aniline.
    Type: Grant
    Filed: November 1, 1976
    Date of Patent: February 21, 1978
    Assignee: Sterling Drug Inc.
    Inventors: Karl O. Gelotte, Andrew W. Zalay, Malcolm R. Bell
  • Patent number: 4072746
    Abstract: Compounds useful as cardiotonic agents are 1-R-3-Q-5-PY-2(1H)-pyridinones (I) where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, Q is amino (preferred), lower-alkylamino, di-(lower-alkyl)amino or NHAc, Ac is lower-alkanoyl or lower-carbalkoxy, and PY is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents. The corresponding compounds where Q is nitro, carbamyl, cyano, halo or hydrogen are useful as intermediates and those where Q is hydrogen or cyano also are useful as cardiotonic agents. Said compounds are prepared: by reacting .alpha.-PY-.beta.-(R.sub.1 R.sub.2 N)acrolein (II) with malonamide to produce 1,2-dihydro-2-oxo-5-PY-nicotinamide (Ia) and reacting Ia with a reagent capable of converting carbamyl to amino to produce 3-amino-5-PY-2(1H)-pyridinone (Ib); by reacting II or .alpha.-PY-malonaldehyde (II') with .alpha.
    Type: Grant
    Filed: July 21, 1976
    Date of Patent: February 7, 1978
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Chester J. Opalka, Jr.
  • Patent number: 4055588
    Abstract: 4-(3-Nitrophenyl)pyridine, an intermediate useful in the preparation of 1-(lower-alkyl)-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylates, which are useful as antibacterial agents, is prepared by reacting 3-nitrobenzaldehyde with two molar equivalents of di-(lower-alkyl) oxalacetate (II) in the presence of a catalytic condensing agent, preferably piperidine and/or its acetate, to produce tetra-(lower-alkyl) 3-(3-nitrophenyl)-1,5-pentanedione-1,2,4,5-tetracarboxylate (III), reacting III with ammonia to produce tetra-(lower-alkyl) 1,4-dihydro-4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylate (IV), oxidizing IV to produce tetra-(lower-alkyl) 4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylate (V), hydrolyzing V to produce 4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylic acid (VI) and decarboxylating VI to produce 4-(3-nitrophenyl)pyridine (VI). Intermediates III, IV, V and VI are novel.
    Type: Grant
    Filed: August 18, 1976
    Date of Patent: October 25, 1977
    Assignee: Sterling Drug Inc.
    Inventors: Philip M. Carabateas, Gordon L. Williams
  • Patent number: 4053475
    Abstract: N--R.sub.3 --N--R.sub.4 --N'--(2--Q--5--R.sub.1 --6--R.sub.2 --4-Pyrimidinyl)ureas which are useful as anti-allergic agents are prepared by reacting a 2--Q--4--RNH--5--R.sub.1 --6--R.sub.2 -pyrimidine with an R.sub.4 '-isocyanate and reacting the intermediate product with 1,1'-carbonyldiimidasole.
    Type: Grant
    Filed: July 12, 1976
    Date of Patent: October 11, 1977
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4032523
    Abstract: Compounds useful as anti-allergic agents are 2-Q-4-[XZC=C(R)NH]-5-R.sub.1 -6-R.sub.2 -pyrimidines (I), where Q is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents or N-oxide thereof, R is hydrogen or lower-alkyl, R.sub.1 is hydrogen, lower-alkyl or cyano, R.sub.2 is hydrogen, lower-alkyl, hydroxy or halo, X and Z are the same or different and are each selected from lower-carbalkoxy, lower-alkanoyl, carbamyl and cyano, or ##STR1## is ##STR2## where R.sub.3 and R.sub.4 are each lower-alkyl, or X is hydrogen, are prepared by reacting 4-amino-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidine (II where Q' is amino) with R'O--C(R)=CXZ (III). Preparations of II are given. Also shown as intermediates and/or anti-allergic agents are 4-(AcNH)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (IV) and 4-(R.sub.5 R.sub.6 N)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (V) where Ac is lower-alkanoyl or lower-carbalkoxy, R.sub.5 is hydrogen, lower-alkyl or lower-hydroxyalkyl, and R.sub.
    Type: Grant
    Filed: July 23, 1976
    Date of Patent: June 28, 1977
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4026900
    Abstract: 3-(4 OR 3-Pyridinyl)-2-cyclohexen-1-ones (I) and their oxime derivatives are useful in preparing (3-aminophenyl)-pyridines, in turn, useful in preparing known antibacterial agents. Also shown is the preparation of I by starting with the reaction of methyl vinyl ketone with either 1-(pyridinyl)-1-(lower-tertiary-amino)-ethylene (II) or lower-alkyl 3-(pyridinyl)-3-oxopropanoate. Also shown is the process of converting I to its oxime, acylating the oxime and heating the acylated oxime under acidic conditions to produce N-(lower-acyl)-3-(pyridinyl)-aniline (VII), and hydrolyzing VII under aqueous alkaline conditions to produce the corresponding 3-(pyridinyl)aniline.
    Type: Grant
    Filed: March 19, 1976
    Date of Patent: May 31, 1977
    Assignee: Sterling Drug Inc.
    Inventors: Karl O. Gelotte, Andrew W. Zalay, Malcolm R. Bell
  • Patent number: 4021437
    Abstract: Improvements in the reduction of 6-acetamido-2-picoline to produce 6-ethylamino-2-picoline, the improvements being in the use of diborane as the reducing agent and in the use of a low boiling petroleum solvent to separate the soluble 6-ethylamino-2-picoline from the insoluble starting material 6-acetamido-2-picoline. The 6-ethylamino-2-picoline final product is useful as an intermediate in a known method of preparing nalidixic acid, an antibacterial agent.
    Type: Grant
    Filed: March 15, 1976
    Date of Patent: May 3, 1977
    Assignee: Sterling Drug Inc.
    Inventor: Roman R. Lorenz
  • Patent number: 4018770
    Abstract: Compounds useful as anti-allergic agents are 2-Q-4-[XZC=C(R)NH]-5-R.sub.1 -6-R.sub.2 -pyrimidines (I), where Q is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents or N-oxide thereof, R is hydrogen or lower-alkyl, R.sub.1 is hydrogen, lower-alkyl or cyano, R.sub.2 is hydrogen, lower-alkyl, hydroxy or halo, X and Z are the same or different and are each selected from lower-carbalkoxy, lower-alkanoyl, carbamyl and cyano, or ##STR1## where R.sub.3 and R.sub.4 are each lower-alkyl, or X is hydrogen, are prepared by reacting 4-amino-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidine (II where Q' is amino) with R'O-C-(R)=CXZ (III). Preparations of II are given. Also shown as intermediates and/or anti-allergic agents are 4-(AcNH)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (IV) and 4-(R.sub.5 R.sub.6 N)-2-Q-5-R.sub.1 -6-R.sub.2 -pyrimidines (V) where Ac is lower-alkanoyl or lower-carbalkoxy, R.sub.5 is hydrogen, lower-alkyl or lower-hydroxyalkyl, and R.sub.
    Type: Grant
    Filed: March 3, 1975
    Date of Patent: April 19, 1977
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4009208
    Abstract: 4-(Q-O)-4'-R.sub.1 -N,N'-alkylenebis(benzamides), N,N'-alkylenebis(3,4-methylenedioxybenzamides) or N,N'-alkylenebis[4-(lower-alkoxy)benzamides], having endocrinological properties, where Q is lower-alkyl, lower-alkoxyalkyl, lower-alkenyl, halo-lower-alkyl, halo-lower-alkenyl, lower-cycloalkyl, phenyl and BN-(lower-alkyl) where BN is di-(lower-alkyl)amino or a saturated N-heteromonocyclic radical having from five to seven ring atoms and alkylene has at least five carbon atoms between its two connecting linkages and R.sub.1 is Q-O-, hydrogen, lower-alkoxy, lower-alkyl, halo, benzyloxy, hydroxy, di-(lower-alkyl)amino, nitro, amino or trihalomethyl are prepared preferably by reacting the appropriate diamine or N-(aminoalkyl)-benzamide with two or one molar equivalents, respectively, of the appropriate benzoyl halide.
    Type: Grant
    Filed: November 21, 1972
    Date of Patent: February 22, 1977
    Assignee: Sterling Drug Inc.
    Inventor: George Y. Lesher
  • Patent number: 4008239
    Abstract: 4-(3-Nitrophenylpyridine and intermediate useful in the preparation of 1-(lower-alkyl)-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylates, which are useful as antibacterial agents, is prepared by reacting 3-nitrobenzaldehyde with two molar equivalents of di-(lower-alkyl) oxalacetate (II) in the presence of a catalytic condensing agent, preferably piperidine and/or its acetate, to produce tetra-(lower-alkyl) 3-(3-nitrophenyl)-1,5-pentanedione-1,2,4,5-tetracarboxylate (III), reacting III with ammonia to produce tetra-(lower-alkyl) 1,4-dihydro-4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylate (IV), oxidizing IV to produce tetra-(lower-alkyl) 4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylate (V), hydrolyzing V to produce 4-(3-nitrophenyl)-2,3,5,6-pyridinetetracarboxylic acid (VI) and decarboxylating VI to produce 4-(3-nitrophenyl)pyridine (VI). Intermediates III, IV, V and VI are novel.
    Type: Grant
    Filed: February 20, 1976
    Date of Patent: February 15, 1977
    Assignee: Sterling Drug Inc.
    Inventors: Philip M. Carabateas, Gordon L. Williams
  • Patent number: 4008235
    Abstract: Compounds useful as anti-allergic agents are N-R.sub.3 -N-R.sub.4 -N'-R-N'-(2-Q-5-R.sub.1 -6-R.sub.2 -4-pyrimidinyl)ureas (I), where Q is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents or N-oxide thereof, R is hydrogen or lower-alkyl, R.sub.1 is hydrogen, lower-alkyl or cyano, R.sub.2 is hydrogen or lower-alkyl, R.sub.3 is hydrogen, lower-alkyl or lower-hydroxyalkyl, R.sub.4 is hydrogen, lower-alkyl, lower-hydroxyalkyl, lower-alkenyl or lower-cycloalkyl. Said ureas are prepared by reacting 2-Q-4-RNH-5-R.sub.1 -6-R.sub.2 -pyrimidine (II) with a carbamylating agent selected from an R.sub.4 '-isocyanate of the formula R.sub.4 'N=C=O to produce N-R.sub.4 '-N'-R-N'-(2-Q-5-R.sub.1 -6-R.sub.2 -4-pyrimidinyl)urea (IA), an N-R.sub.3 '-N-R.sub.4 '-carbamyl halide of the formula R.sub.3 'R.sub.4 'NC(=O)-halide to produce N-R.sub.3 '-N-R.sub.4 'N'-R-N'-(2-Q-5-R.sub.1 -6-R.sub.2 -4-pyrimidinyl)urea (IB) or 1,1'-carbonyldiimidazole to produce N-(2-Q-5-R.sub.1 -6-R.sub.
    Type: Grant
    Filed: March 7, 1975
    Date of Patent: February 15, 1977
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4004012
    Abstract: Compounds useful as cardiotonic agents are 1-R-3-Q-5-PY-2(1H)-pyridinones (I) where R is hydrogen, loweralkyl or lower-hydroxyalkyl, Q is amino (preferred) or NHAc, Ac is lower-alkanoyl or lower-carbalkoxy, and PY is 4- or 3- or 2-pyridinyl or 4- or 3- or 2-pyridinyl having one or two lower-alkyl substituents. The corresponding compounds where Q is nitro, carbamyl, cyano or hydrogen are useful as intermediates and those where Q is hydrogen or cyano also are useful as cardiotonic agents. Said compounds are prepared: by reacting .alpha.-PY-.beta.-(R.sub.1 R.sub.2 N)acrolein (II) with malonamide to produce 1,2-dihydro-2-oxo-5-PY-nicotinamide (Ia) and reacting Ia with a reagent capable of converting carbamyl to amino to produce 3-amino-5-PY-2(1H)-pyridone (Ib); by reacting II or .alpha.-PY-malonaldehyde (II') with .alpha.
    Type: Grant
    Filed: October 14, 1975
    Date of Patent: January 18, 1977
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Chester Joseph Opalka
  • Patent number: 3997542
    Abstract: Compounds useful as antiamebic agents are 1-(Ac.sub.1)-5-R-6-(Ac.sub.2 O)-1,2,3,4-tetrahydroquinolines (I), where Ac.sub.1 is haloacetyl, dihaloacetyl or trihaloacetyl with halo being chloro or bromo, R is hydrogen, chloro or bromo, and Ac.sub.2 is hydrogen, Ac.sub.1, alkanoyl having from one to sixteen carbon atoms, benzoyl, 2(or 3)-thenoyl, 2(or 3)-furoyl or N-(lower-alkyl)carbamoyl. Said compounds are prepared: by reacting 1,2,3,4-tetrahydro-6-quinolinol with an acyl halide of the formula Ac.sub.1 -halogen to produce 1-(Ac.sub.1)-1,2,3,4-tetrahydro-6-quinolinol having formula I where R and Ac.sub.2 are each hydrogen, Ac.sub.1 is defined as in formula I and halide is chloride or bromide; by reacting said 1-(Ac.sub.1)-1,2,3,4-tetrahydro-6-quinolinol with a chlorinating or brominating agent to produce the corresponding 1-(Ac.sub.1)-5-chloro(or bromo)-1,2,3,4-tetrahydro-6-quinolinol where Ac.sub.1 is defined as in claim 1; and, by reacting 1-(Ac.sub.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: December 14, 1976
    Assignee: Sterling Drug Inc.
    Inventor: Denis Mahlon Bailey
  • Patent number: 3994903
    Abstract: 4-(3-NITROPHENYL)PYRIDINE, AN INTERMEDIATE USEFUL IN THE PREPARATION OF THE ANTIBACTERIALLY ACTIVE 1-ALKYL-1,4-DIHYDRO-4-OXO-7-(4-PYRIDYL)-3-QUINOLINECARBOXYLIC ACIDS, IS PREPARED BY REACTING 4-(4-DIMETHYLAMINOPHENYL)PYRIDINE (I) with a demethylating agent to yield 4-(4-aminophenyl)pyridine (II), reacting said 4-aminophenyl compound (II) with a lower-alkanoylating agent to yield 4-[4-(lower-alkanoylamino)-phenyl]pyridine (III), nitrating the 4-(lower-alkanoylamino)-phenyl derivative (III) to yield 4-[4-(lower-alkanoylamino)-3-nitrophenyl]pyridine (IV), hydrolyzing the 4-(lower-alkanoylamino)-3-nitrophenyl compound (IV) to yield 4-(4-amino-3-nitrophenyl)-pyridine (V), and removing the 4-amino group of V by diazotization and reaction of the diazonium salt with a deaminating reducing agent to produce said intermediate 4-(3-nitrophenyl)pyridine (VI). Intermediates IV and V are novel.
    Type: Grant
    Filed: February 25, 1974
    Date of Patent: November 30, 1976
    Assignee: Sterling Drug Inc.
    Inventors: Philip M. Carabateas, Ruth Pauline Brundage
  • Patent number: 3992380
    Abstract: Antibacterial 5,8-dihydro-8-(lower-alkyl)-5-oxo-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (I) where Z is carboxy or lower-carbalkoxy, R.sub.2 is hydrogen or lower-alkyl and Q is 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents is prepared by heating di-(lower-alkyl) N-(2-Q-6-R.sub.2 -4-pyrimidinyl)aminomethylenemalonate (III) to produce 5,8-dihydro-5-oxo-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (II) which is tautomeric with 5-hydroxy-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (IIA) where Q and R.sub.2 are the same as in I above and Z is lower-carbalkoxy, reacting II(or IIA) with a lower-alkylating agent to produce I where Z is lower-carbalkoxy and hydrolyzing this ester (I) to produce I where Z is carboxy. Alternatively, the acid (II or IIA where Z is COOH) can be alkylated after first hydrolyzing the ester (II or IIA where Z is lower-carbalkoxy). The preparations of the intermediate III and intermediates used in its preparation are given.
    Type: Grant
    Filed: March 3, 1975
    Date of Patent: November 16, 1976
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh