Patents by Inventor Baldev Singh

Baldev Singh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4634772
    Abstract: 2-[2-(di-lower-alkylamino-1-propenyl]-6-methoxy-3-pyridinecarbonitriles, useful as intermediates for cardiotonic agents.
    Type: Grant
    Filed: January 6, 1986
    Date of Patent: January 6, 1987
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4604399
    Abstract: 4-R'-5-Q-1,6-naphthyridin-2(1H)-ones (I), where R' is hydrogen or methyl and Q is hydroxymethyl, 1-hydroxyethyl alkanoyloxymethyl or 1-alkanoyloxyethyl, are produced by first reacting 4-R'-5-acetyl(or n-propanoyl)-6-[2-(di-lower-alkylamino]-2(1H)-pyridinone [III] with hydroxylamine or salt thereof to produce 4-R'-5-Q'-1,6-naphthyridin-2(1H)-one-6-oxide (II), where R' is defined as above and Q' is methyl or ethyl; next reacting II with an alkanoic anhydride to produce I where Q is alkanoyloxymethyl or 1-alkanoyloxyethyl; and, then hydrolyzing said alkanoyloxymethyl or -ethyl compound to produce I where Q is hydroxymethyl or 1-hydroxyethyl. Also shown is the cardiotonic use of II and I where Q is hydroxymethyl, 1-hydroxyethyl or alkanoyloxymethyl.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: August 5, 1986
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4595762
    Abstract: 3-Q-4-R.sub.2 -5-(2-Q'-5-R.sub.3 -4-thiazolyl)-6-R.sub.1 -2(1H)-pyridinones (I), where R.sub.1 is alkyl having from one to four carbon atoms, R.sub.2 is hydrogen or methyl, R.sub.3 is hydrogen or alkyl having from one to three carbon atoms, Q is amino, carbamyl, carboxy, cyano or hydrogen, and Q' is alkyl having from one to four carbon atoms, amino or R.sub.4 NH where R.sub.4 is alkyl having from one to four carbon atoms, or acid-addition salts thereof where at least one of Q and Q' is amino or Q' is R.sub.4 NH, are useful as cardiotonics (I where Q is amino, cyano or hydrogen) and/or as intermediates (I where Q is cyano, carbamyl or carboxy). Also shown as intermediates are 1,2-dihydro-4-R.sub.2 -5-[R.sub.3 CH(Br)CO]-6-R.sub.1 -2-oxo-3-pyridinecarbonitriles (II), and, also, processes for preparing I and II.
    Type: Grant
    Filed: February 13, 1985
    Date of Patent: June 17, 1986
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4567186
    Abstract: 3-Z-5-Q-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where Z is hydrogen or cyano, and Q is 2(or 3)-furanyl, 2(or 3)-thienyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two methyl substituents, are useful as cardiotonic agents and corresponding compounds where Z is carboxy are useful as intermediates. Also shown as intermediates are 5-(Q-CO)-6-[2-(di-lower-alkylamino)ethenyl]-2(1H)-pyridinones (II) or salts thereof, where Q is defined as above. Processes for preparing said compounds (I and II) are shown.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: January 28, 1986
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4560753
    Abstract: 2-Q-6-Q'-8-R-pyrido[2,3-d]pyrimidin-5(8H)-ones (I), where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-methoxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents, R' is hydrogen or alkyl having one to four carbon atoms, Q is hydrogen, amino or nitro, and R is alkyl having from one to four carbon atoms, CH(C.sub.2 H.sub.5).sub.2, (CH.sub.2).sub.n .dbd.CHCH.sub.2 where n is 1 or 2, or Y--Z where Y is alkylene having from two to four carbon atoms and having its connecting linkages on different carbon atoms and Z is hydroxy, OR.sub.1 or NR.sub.1 R.sub.2 where R.sub.1 and R.sub.2 are each methyl or ethyl, or acid-addition salts thereof, and their preparation are shown. Also shown is the cardiotonic use of I where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents and Q' is hydrogen or amino.
    Type: Grant
    Filed: October 12, 1983
    Date of Patent: December 24, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh, Stanley C. Laskowski
  • Patent number: 4560691
    Abstract: 1-R-5-Ar-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where R is hydrogen or methyl, and Ar is phenyl or phenyl substituted by methyl, ethyl, methoxy, ethoxy, hydroxy, amino, acetylamino, methanesulfonylamino, bromo, chloro, fluoro, cyano or carbamyl are useful as cardiotonic agents and corresponding compounds where Ar is nitrophenyl are useful as intermediates. Also shown as intermediates, are 5-(Ar--CO)-6-[2-(di-lower-alkylamino)-ethenyl]-2(1H)-pyridinones (II) or salts thereof, where Ar is phenyl or phenyl substituted by methyl, ethyl, methoxy, ethoxy, bromo, chloro, fluoro, cyano or nitro and 5-(Ar--CO)-6-methyl-2(1H)-pyridinones (III) where Ar is phenyl or phenyl substituted by methyl, ethyl, methoxy, ethoxy, bromo, chloro, fluoro, hydroxy, cyano or nitro; said compounds (III) where Ar is phenyl or hydroxyphenyl also are useful as cardiotonic agents. Processes for preparing the compounds of formulas I, II and III are shown.
    Type: Grant
    Filed: July 13, 1984
    Date of Patent: December 24, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4559347
    Abstract: 1-R"-3-Q-4-R'-5-R-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where R is lower-alkyl, R' is hydrogen or methyl, R" is hydrogen or lower-alkyl, and Q is hydrogen, hydroxy, amino, cyano, carbamyl, carboxy or aminocarbamyl, are useful as cardiotonic agents (I, Q is hydrogen, hydroxy, amino, cyano or carbamyl) and/or intermediates therefor (I, Q is carboxy, aminocarbamyl, hydrogen, amino, cyano or carbamyl). Also shown are 3-Q'-4-R'-5-(RCO)-6-[2-di-lower-alkylamino)ethenyl]-2(1H)-pyridinones (II) or salts thereof, where R and R' are as above and Q' is hydrogen or cyano, which are useful as cardiotonics (II, Q' is hydrogen) and/or intermediates (II, Q' is cyano or hydrogen). Processes for preparing the compounds of formulas I and II are shown.
    Type: Grant
    Filed: October 11, 1984
    Date of Patent: December 17, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4539327
    Abstract: 3-Q-4-R.sub.2 -5-(2-Q'-5-R.sub.3 -4-thiazolyl)-6-R.sub.1 -2(1H)-pyridinones (I), where R.sub.1 is alkyl having from one to four carbon atoms, R.sub.2 is hydrogen or methyl, R.sub.3 is hydrogen or alkyl having from one to three carbon atoms, Q is amino, carbamyl, carboxy, cyano or hydrogen, and Q' is alkyl having from one to four carbon atoms, amino or R.sub.4 NH where R.sub.4 is alkyl having from one to four carbon atoms, or acid-addition salts thereof where at least one of Q and Q' is amino or Q' is R.sub.4 NH, are useful as cardiotonics (I where Q is amino, cyano or hydrogen) and/or as intermediates (I where Q is cyano, carbamyl or carboxy). Also shown as intermediates are 1,2-dihydro-4-R.sub.2 -5-[R.sub.3 CH(Br)CO]-6-R.sub.1 -2-oxo-3-pyridinecarbonitriles (II), and, also, processes for preparing I and II.
    Type: Grant
    Filed: January 16, 1984
    Date of Patent: September 3, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4532247
    Abstract: 4-R'-5-Q-1,6-naphthyridin-2(1H)-ones (I), where R' is hydrogen or methyl and Q is hydroxymethyl, 1-hydroxyethyl alkanoyloxymethyl or 1-alkanoyloxyethyl, are produced by first reacting 4-R'-5-acetyl(or n-propanoyl)-6-[2-(di-lower-alkylamino]-2(1H)-pyridinone [III] with hydroxylamine or salt thereof to produce 4-R'-5-Q'-1,6-naphthyridin-2(1H)-one-6-oxide (II), where R' is defined as above and Q' is methyl or ethyl; next reacting II with an alkanoic anhydride to produce I where Q is alkanoyloxymethyl or 1-alkanoyloxyethyl; and, then hydrolyzing said alkanoyloxymethyl or -ethyl compound to produce I where Q is hydroxymethyl or 1-hydroxyethyl. Also shown is the cardiotonic use of II and I where Q is hydroxymethyl, 1-hydroxyethyl or alkanoyloxymethyl.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: July 30, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4524149
    Abstract: 4-R.sub.2 -5-(Lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones (I), useful as cardiotonics, where R.sub.2 is hydrogen or methyl, are prepared by reacting 2-(lower-alkanoyl)-1-(lower-alkyl)ethenamine (II) with lower-alkyl 2-propynoate or 2-butynoate respectively or by hydrolyzing 4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinonitrile (III), Q is CN) or corresponding 4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinamide to produce the corresponding 5-(lower-alkanoyl)-6-(lower-alkyl)-1,2-dihydro-2-oxonicotinic acid and decarboxylating said substituted nictotinic acid to produce I. Also disclosed and claimed are cardiotonic uses of 3-Q-4-R.sub.2 -5-(lower-alkanoyl)-6-(lower-alkyl)-2(1H)-pyridinones where Q is hydrogen or cyano and R.sub.2 is hydrogen or methyl (III). Also shown and claimed is methyl 4-acetyl-5-amino-2,4-hexadienoate or acid-addition salt thereof, useful as intermediate or cardiotonic.
    Type: Grant
    Filed: February 7, 1983
    Date of Patent: June 18, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4517190
    Abstract: 1-R"-3-Q-4-R'-5-R-1,6-naphthyridin-2(1H)-ones (I) or salts thereof, where R is lower-alkyl, R' is hydrogen or methyl, R" is hydrogen or lower-alkyl, and Q is hydrogen, hydroxy, amino, cyano, carbamyl, carboxy or aminocarbamyl, are useful as cardiotonic agents (I, Q is hydrogen, hydroxy, amino, cyano or carbamyl) and/or intermediates therefor (I, Q is carboxy, aminocarbamyl, hydrogen, amino, cyano or carbamyl). Also shown are 3-Q'-4-R'-5-(RCO)-6-[2-(di-lower-alkylamino)ethenyl]-2(1H)-pyridinones (II) or salts thereof, where R and R' are as above and Q' is hydrogen or cyano, which are useful as cardiotonics (II, Q' is hydrogen) and/or intermediates (II, Q' is cyano or hydrogen). Processes for preparing the compounds of formulas I and II are shown.
    Type: Grant
    Filed: June 9, 1983
    Date of Patent: May 14, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4512993
    Abstract: Shown are 2-(NB)-4-PY-5-Q-pyrimidines (I) and 2-(NB')-5-PY-4-Q'-pyrimidines (II) or salts thereof, where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, Q and Q' are each hydrogen or methyl, NB is dimethylamino or N-(2-hydroxyethyl)methylamino and NB' is amino, dimethylamino, acetylamino or propionylamino; the preparation thereof; and, their cardiotonic use.
    Type: Grant
    Filed: July 25, 1983
    Date of Patent: April 23, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4506075
    Abstract: 3-Methyl-4-(4-pyridinyl)benzeneamines, useful as cardiotonic agents, are prepared by reaction of pyridine, benzoyl chloride and an appropriate 3-methyl-N,N-di-lower-alkylbenzeneamine in the presence of copper powder and decomposing the reaction mixture with alkali and, if desired, reacting a resulting 3-methyl-4-(4-pyridinyl)N,N-di-lower-alkylbenzeneamine with hydrogen bromide and pyridine to obtain 3-methyl-4-(4-pyridinyl)benzeneamine.
    Type: Grant
    Filed: April 14, 1983
    Date of Patent: March 19, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4504482
    Abstract: N-R-N'-R'-N-[4(or 5)-PY-2-pyrimidinyl]ureas (I) or salts thereof, where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, R' is hydrogen or methyl and R is methyl or ethyl when PY is attached to the 4-position of the pyrimidine ring or R is hydrogen, ethyl or n-butyl when PY is attached to the 5-position of the pyrimidine ring are useful as cardiotonic agents. The preparations of I and their cardiotonic use are shown.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: March 12, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4503228
    Abstract: 8-Q-2-PY-9H-purin-6-amines (II), salts thereof, their preparation via 2-PY-4,5,6-pyrimidinetriamine and cardiotonic use are shown, where PY is 4-pyridinyl or 4-pyridinyl having one or two lower-alkyl substituents, and Q is methyl, ethyl, 1-methylethyl, 1,1-dimethylethyl, methylthio and ethylthio. Also shown as intermediates for the compounds where Q is methylthio or ethylthio are the corresponding 6-amino-2-PY-9H-purin-8-thiols.
    Type: Grant
    Filed: May 21, 1984
    Date of Patent: March 5, 1985
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4473571
    Abstract: 8-Q-2-PY-9H-purin-6-amines (II), salts thereof, their preparation and cardiotonic use are shown, where PY is 4-pyridinyl or 4-pyridinyl having one or two lower-alkyl substituents, and Q is methyl, ethyl, 1-methylethyl, 1,1-dimethylethyl, methylthio and ethylthio. Also shown as intermediates for the compounds where Q is methylthio or ethylthio are the corresponding 6-amino-2-PY-9H-purin-8-thiols.
    Type: Grant
    Filed: January 17, 1983
    Date of Patent: September 25, 1984
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4469699
    Abstract: 3-Q-4-R.sub.2 -5-(2-Q'-5-R.sub.3 -4-thiazolyl)-6-R.sub.1 -2(1H)-pyridinones (I), where R.sub.1 is alkyl having from one to four carbon atoms, R.sub.2 is hydrogen or methyl, R.sub.3 is hydrogen or alkyl having from one to three carbon atoms, Q is amino, carbamyl, carboxy, cyano or hydrogen, and Q' is alkyl having from one to four carbon atoms, amino or R.sub.4 NH where R.sub.4 is alkyl having from one to four carbon atoms, or acid-addition salts thereof where at least one of Q and Q' is amino or Q' is R.sub.4 NH, are useful as cardiotonics (I where Q is amino, cyano or hydrogen) and/or as intermediates (I where Q is cyano, carbamyl or carboxy). Also shown as intermediates are 1,2-dihydro-4-R.sub.2 -5-[R.sub.3 CH(Br)CO]-6-R.sub.1 -2-oxo-3-pyridinecarbonitriles (II), and, also, processes for preparing I and II.
    Type: Grant
    Filed: August 25, 1982
    Date of Patent: September 4, 1984
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh
  • Patent number: 4463008
    Abstract: 2-(R.sub.1 O)-3-Q-5-PY-6-R-pyridine (I) or pharmaceutically acceptable acid-addition salts thereof are useful cardiotonics, where R.sub.1 is methyl or ethyl, R is hydrogen or lower-alkyl, PY is 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents, and Q is hydrogen, chloro or COOR' where R' is lower-alkyl, or Q is cyano only when R is hydrogen. The preparation of I and their cardiotonic use are shown.
    Type: Grant
    Filed: November 10, 1982
    Date of Patent: July 31, 1984
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Chester J. Opalka, Jr., Baldev Singh
  • Patent number: 4451469
    Abstract: 3-Q-4-R'-6-R-2(1H)-pyridinones (I), where Q is hydrogen or cyano, R' is hydrogen, methyl, ethyl or n-propyl, and R is methyl, ethyl or n-propyl, are shown to be useful as cardiotonic agents.
    Type: Grant
    Filed: December 16, 1982
    Date of Patent: May 29, 1984
    Assignee: Sterling Drug Inc.
    Inventors: Baldev Singh, George Y. Lesher
  • Patent number: 4432981
    Abstract: 2-Q-6-Q'-8-R-pyrido[2,3-d]pyrimidin-5(8H)-ones (I), where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-methoxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents, R' is hydrogen or alkyl having one to four carbon atoms, Q is hydrogen, amino or nitro, and R is alkyl having from one to four carbon atoms, CH(C.sub.2 H.sub.5).sub.2, (CH.sub.2).sub.n .dbd.CHCH.sub.2 where n is 1 or 2, or Y-Z where Y is alkylene having from two to four carbon atoms and having its connecting linkages on different carbon atoms and Z is hydroxy, OR.sub.1 or NR.sub.1 R.sub.2 where R.sub.1 and R.sub.2 are each methyl or ethyl, or acid-addition salts thereof, and their preparation are shown. Also shown is the cardiotonic use of I where Q is 4(or 3)-hydroxyphenyl, 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents and Q' is hydrogen or amino.
    Type: Grant
    Filed: November 5, 1982
    Date of Patent: February 21, 1984
    Assignee: Sterling Drug Inc.
    Inventors: George Y. Lesher, Baldev Singh, Stanley C. Laskowski