Patents by Inventor S.M. Dileep Kumar

S.M. Dileep Kumar 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: 6919450
    Abstract: The present invention relates to an improved process for the preparation of trifluoromethanesulfonic ester of ethyl (R)-2-hydroxy-4-phenylbutyrate, referred to here as triflate in structural Formula I, and to the use of this compound as intermediate for the preparation of ACE (Angiotensin Converting Enzyme) inhibitor, benazepril.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: July 19, 2005
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Rajest Kumar Thaper, Yatendra Kumar, Shantanu De, S.M. Dileep Kumar
  • Publication number: 20040152889
    Abstract: The present invention relates to an improved process for the preparation of trifluoromethanesulfonic ester of ethyl (R)-2-hydroxy-4-phenylbutyrate, referred to here as triflate in structural Formula I, and to the use of this compound as intermediate for the preparation of ACE (Angiotensin Converting Enzyme) inhibitor, benazepril.
    Type: Application
    Filed: March 30, 2004
    Publication date: August 5, 2004
    Inventors: Rajest Kumar Thaper, Yatendra Kumar, Shantanu De, S M Dileep Kumar
  • Publication number: 20030149279
    Abstract: A process for the preparation of amorphous atorvastatin calcium and hydrates thereof which comprises: (a) dissolving crystalline atorvastatin calcium in a non-hydroxylic solvent; (b) adding a non-polar hydrocarbon anti-solvent or adding the dissolved atorvastatin to the non-polar anti-solvent to precipitate out atorvastatin calcium; and (c) removing the solvent by filtration to afford amorphous atorvastatin calcium.
    Type: Application
    Filed: March 3, 2003
    Publication date: August 7, 2003
    Inventors: Yatendra Kumar, Rajesh Kumar Thaper, S. M. Dileep Kumar
  • Patent number: 6528660
    Abstract: A process for the preparation of amorphous atorvastatin calcium and hydrates thereof which comprises: (a) dissolving crystalline atorvastatin calcium in a non-hydroxylic solvent; (b) adding a non-polar hydrocarbon anti-solvent or adding the dissolved atorvastatin to the non-polar anti-solvent to precipitate out atorvastatin calcium; and (c) removing the solvent by filtration to afford amorphous atorvastatin calcium.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: March 4, 2003
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Yatendra Kumar, Rajesh Kumar Thaper, S. M. Dileep Kumar
  • Patent number: 5939564
    Abstract: A novel process of lactonizaton in the preparation of statins (e.g., the HMG--CoA reductase inhibitors lovastatin and simvastatin) employs very mild reaction conditions. The improved process comprises dissolving the open ring hydroxy acid form of the statins in an organic solvent by heating at a temperature, which ranges from ambient to reflux of the solvent, under anhydrous conditions to produce a solution, treating the solution with a mild catalyst at a temperature from about ambient to 50.degree. C., and adding water to the solution to cause the statins in lactone form to crystalize from the reaction mixture. The mild catalyst used in the reaction is a salt of an organic base with an organic or inorganic acid, such as pyridine hydrobromide, pyridine hydrochloride, or pyridinium, p-toluene sulfonate. The organic solvent comprises a lower alkanol, a non-alcoholic polar solvent, or a mixture of the two.
    Type: Grant
    Filed: April 6, 1998
    Date of Patent: August 17, 1999
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Yatendra Kumar, Rajesh Kumar Thaper, S. M. Dileep Kumar, Jag Mohan Khanna
  • Patent number: 5917058
    Abstract: An improved process of lactonization in the preparation of statins (e.g., the HMG--CoA reductase inhibitors lovastatin and simvastatin) employs very mild reaction conditions. The improved process comprises treating the open ring hydroxy acid form of the statins with an excess of acetic acid and in the absence of a strong acid catalyst under mild heating conditions (e.g., ambient to 55.degree. C.), and adding an anti-solvent to the reaction mixture, thereby causing the statins in lactone form to crystalize from the reaction mixture. The acetic acid serves as both a solvent and a catalyst for the lactonization reaction.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: June 29, 1999
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Yatendra Kumar, Rajesh Kumar Thaper, S. M. Dileep Kumar, Jag Mohan Khanna
  • Patent number: 5763646
    Abstract: A process for preparing simvastatin from lovastatin or mevinolinic acid in salt form comprises treating either starting material with cyclopropyl or butyl amine, the pyranone ring thereby being opened when lovastatin is the starting material, adding a methyl group to the 2-methylbutyrate side chain, and thereafter closing the open pyranone ring to produce simvastatin. The process is performed without protecting and deprotecting the two hydroxy groups of the open pyranone ring. In a preferred embodiment, the starting material is treated with cyclopropyl amine which produces simvastatin via the novel intermediate lovastatin cyclopropyl amide.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: June 9, 1998
    Assignee: Ranbaxy Laboratories, Ltd.
    Inventors: Yatendra Kumar, Rajesh Kumar Thaper, Satyananda Misra, S. M. Dileep Kumar, Jag Mohan Khanna
  • Patent number: 5763653
    Abstract: A process for preparing simvastatin from lovastatin or mevinolinic acid in salt form comprises treating either starting material with cyclopropyl or butyl amine, the pyranone ring thereby being opened when lovastatin is the starting material, adding a methyl group to the 2-methylbutyrate side chain, and thereafter closing the open pyranone ring to produce simvastatin. The process is performed without protecting and deprotecting the two hydroxy groups of the open pyranone ring. In a preferred embodiment, the starting material is treated with cyclopropyl amine which produces simvastatin via the novel intermediate lovastatin cyclopropyl amide.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: June 9, 1998
    Assignee: Ranbaxy Laboratories, Ltd.
    Inventors: Jag Mohan Khanna, Yatendra Kumar, Rajesh Kumar Thaper, Satyananda Misra, S. M. Dileep Kumar