Patents by Inventor Nelo R. Rivera

Nelo R. Rivera 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).

  • Process for the preparation of enantiomerically enriched beta amino acid derivatives
    Patent number: 7495123
    Abstract: The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives wherein the amino group is unprotected. The product chiral beta amino acid derivatives are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of an amine-unprotected prochiral beta-amino acrylic acid or derivative thereof in the presence of a rhodium metal precursor complexed with a chiral mono- or bisphosphine ligand.
    Type: Grant
    Filed: April 5, 2005
    Date of Patent: February 24, 2009
    Assignees: Solvias AG, Merck & Co., Inc.
    Inventors: Yi Xiao, Yongkui Sun, Thorsten Rosner, Nelo R. Rivera, Shane W. Krska, Andrew M. Clausen, Joseph D. Armstrong, III, Felix Spindler, Christophe Malan
  • Process for the preparation of chiral beta amino acid derivatives by asymmetric hydrogenation
    Patent number: 7468459
    Abstract: The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives which are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of a prochiral beta amino acrylic acid derivative substrate in the presence of a transition metal precursor complexed with a chiral ferrocenyl diphosphine ligand.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: December 23, 2008
    Assignee: Merck & Co., Inc.
    Inventors: Yi Xiao, Joseph D. Armstrong, III, Shane W. Krska, Eugenia Njolito, Nelo R. Rivera, Yongkui Sun, Thorsten Rosner
  • Process to chiral integrin antagonist beta-amino acid intermediate
    Patent number: 6646130
    Abstract: The invention discloses a novel process for the preparation of enantiomerically enriched mixtures of compounds of structural formula I which are useful intermediates in the synthesis of &agr;v&bgr;3 integrin receptor antagonists
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: November 11, 2003
    Assignee: Merck & Co., Inc.
    Inventors: Nelo R. Rivera, Christopher J. Welch, Yi Xiao, Nobuyoshi Yasuda
  • Process to chiral integrin antagonist beta-amino acid intermediate
    Publication number: 20030045555
    Abstract: The invention discloses a novel process for the preparation of enantiomerically enriched mixtures of compounds of structural formula I which are useful intermediates in the synthesis of &agr;v&bgr;3 integrin receptor antagonists.
    Type: Application
    Filed: July 17, 2002
    Publication date: March 6, 2003
    Inventors: Nelo R. Rivera, Christopher J. Welch, Yi Xiao, Nobuyoshi Yasuda
  • Process and intermediates to a tetrahydro-[1,8]- Naphthyridine
    Patent number: 6423845
    Abstract: A novel process is provided for the preparation of 3-(5,6,7,8-tetrahydro-[1,8]-naphthyridin-2-yl)-propylamine which is useful in the synthesis of &agr;v integrin receptor antagonists. Also provided are useful intermediates obtained from the process.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: July 23, 2002
    Assignee: Merck & Co., Inc.
    Inventors: Nelo R. Rivera, Yi Xiao, Nobuyoshi Yasuda
  • Process and intermediates for the preparation of imidazolidinone &agr;v integrin antagonists
    Patent number: 6407241
    Abstract: A novel process is provided for the preparation of imidazolidinone &agr;v&bgr;3/&agr;v&bgr;5 integrin antagonists, and the useful intermediates obtained therein. These compounds are antagonists of &agr;v&bgr;3/&agr;v&bgr;5 integrin receptors and thus useful for inhibiting bone resorption and treating and preventing osteoporosis. Also disclosed is 3-{2-oxo-3-[3-(5,6,7,8-tetrahydro-[1,8]naphthyridin-2-yl)-propyl]imidazolidin-1-yl}-3(S)-(6-methoxy-pyridin-3-yl)-propionic acid in the form of a hemihydrate.
    Type: Grant
    Filed: November 7, 2000
    Date of Patent: June 18, 2002
    Assignee: Merck & Co., Inc.
    Inventors: Mark S Jensen, Michael Palucki, Nelo R. Rivera, Kenneth M. Wells, Yi Xiao, Yaling Wang, Chunhua Yang, Nobuyoshi Yasuda