Patents by Inventor Bikshandarkoil A. Narayanan

Bikshandarkoil A. Narayanan 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).

  • Polymorph of a pharmaceutical
    Patent number: 9255092
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Grant
    Filed: October 14, 2013
    Date of Patent: February 9, 2016
    Assignee: AbbVie Inc.
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • POLYMORPH OF A PHARMACEUTICAL
    Publication number: 20150031731
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: October 14, 2013
    Publication date: January 29, 2015
    Applicant: AbbVie Inc.
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Polymorph of a pharmaceutical
    Patent number: 8674112
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: March 18, 2014
    Assignee: AbbVie Inc.
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Polymorph of a Pharmaceutical
    Publication number: 20120232284
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: May 25, 2012
    Publication date: September 13, 2012
    Applicant: ABBOTT LABORATORIES
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Polymorph of a pharmaceutical
    Patent number: 8193367
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: June 5, 2012
    Assignee: Abbott Laboratories
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Polymorph of a Pharmaceutical
    Publication number: 20100144804
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: December 22, 2009
    Publication date: June 10, 2010
    Applicant: Abbott Laboratories
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Polymorph of a pharmaceutical
    Patent number: 7659405
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: February 9, 2010
    Assignee: Abbott Laboratories
    Inventors: John F. Bauer, Azita Saleki-Gerhardt, Bikshandarkoil A. Narayanan, Sanjay R. Chemburkar, Ketan M. Patel, Harry O. Spiwek, Philip E. Bauer, Kimberly A. Allen
  • Synthesis of acyclic nucleoside derivatives
    Patent number: 7189849
    Abstract: Novel processes towards the synthesis of the antiviral valomaciclovir stearate in which an esterified guanine acetal is reduced to the corresponding alcohol, reacted with an activated amino acid and N-deprotected. The esterified guanine acetal is prepared from a 9-guanine derivative bearing an acyclic hydroxymethylbutylacetal. The processes are amendable to one-pot reactions.
    Type: Grant
    Filed: May 18, 2005
    Date of Patent: March 13, 2007
    Assignee: Medivir AB
    Inventors: M. Robert Leanna, Michael Rasmussen, Steven M. Hannick, Jien-Heh J. Tien, Kirill A. Lukin, Zhenping Tian, Sou-Jen Chang, Cynthia B. Curty, Bikshandarkoil A. Narayanan, John Bellettini, Bhadra Shelat, Tiffany Spitz
  • Polymorph of a pharmaceutical
    Publication number: 20070015804
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: September 21, 2006
    Publication date: January 18, 2007
    Inventors: John Bauer, Azita Saleki-Gerhardt, Bikshandarkoil Narayanan, Sanjay Chemburkar, Ketan Patel, Harry Spiwek, Philip Bauer, Kimberly Allen
  • Arylation method for the functionalization of O-allyl erythromycin derivatives
    Patent number: 7071314
    Abstract: An efficient arylation technique for use in the synthesis of erythromycin derivatives, involving a modified Heck reaction which employs less than six mole percent of palladium catalyst and no phosphine is disclosed. With this modified Heck reaction, an O-alkenylaryl macrolide can be obtained in a much shorter reaction time than under conventional Heck reaction conditions. The modified Heck reaction can be utilized in a method for phosphine-free arylation of an O-allylic erythromycin derivative, in a method for preparing an O-alkenylaryl erythromycin A derivative, or in a method for preparing a 2?, 4?-hydroxyl protected 6-O-alkenylaryl erythromycin A derivative.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: July 4, 2006
    Assignee: Abbott Laboratories
    Inventors: Weijang Zhang, Margaret Chi-Ping Hsu, Anthony R. Haight, Matthew John Peterson, Bikshandarkoil A. Narayanan
  • Synthesis of acyclic nucleoside derivatives
    Publication number: 20050250795
    Abstract: Methods and novel intermediates for the preparation of acyclic nucleoside derivatives of the formula: where one of R1 and R2 is an amino acid acyl group and the other of R1 and R2 is a —C(O)C3-C21 saturated or monounsaturated, optionally substituted alkyl and R3 is OH or H; or a pharmaceutically acceptable salt thereof.
    Type: Application
    Filed: May 18, 2005
    Publication date: November 10, 2005
    Applicant: Medivir AB
    Inventors: M. Leanna, Steven Hannick, Michael Rasmussen, Jien-Heh Tien, Lakshmi Bhagavatula, Pulla Singam, Bradley Gates, Lawrence Kolaczkowski, Ramesh Patel, Greg Wayne, Greg Lannoye, Weijiang Zhang, Zhenping Tian, Kirill Lukin, Bikshandarkoil Narayanan, David Riley, Howard Morton, Sou-Jen Chang, Cynthia Curty, Daniel Plata, John Bellettini, Bhadra Shelat, Tiffany Spitz, Cheng-Xi Yang
  • Polymorph of a pharmaceutical
    Publication number: 20050203152
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: May 4, 2005
    Publication date: September 15, 2005
    Inventors: John Bauer, Azita Saleki-Gerhardt, Bikshandarkoil Narayanan, Sanjay Chemburkar, Ketan Patel, Harry Spiwek, Philip Bauer, Kimberly Allen
  • Synthesis of acyclic nucleoside derivatives
    Patent number: 6878844
    Abstract: Methods and novel intermediates for the preparation of acyclic nucleoside derivatives of the formula: where one of R1 and R2 is an amino acid acyl group and the other of R1 and R2 is a —C(O)C3-C21 saturated or monounsaturated, optionally substituted alkyl and R3 is OH or H; or a pharmaceutically acceptable salt thereof.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: April 12, 2005
    Assignee: Medivir AB
    Inventors: M. Robert Leanna, Michael Rasmussen, Howard Morton, Zhenping Tian, Daniel Plata, Bradley D. Gates, Bikshandarkoil A. Narayanan
  • Polymorph of a pharmaceutical
    Publication number: 20050009756
    Abstract: A new crystalline polymorph of ritonavir and methods for its use and preparation are disclosed.
    Type: Application
    Filed: July 29, 2004
    Publication date: January 13, 2005
    Inventors: John Bauer, Azita Saleki-Gerhardt, Bikshandarkoil Narayanan, Sanjay Chemburkar, Ketan Patel, Harry Spiwek, Philip Bauer, Kimberly Allen
  • Synthesis of acyclic nucleoside derivatives
    Publication number: 20040248910
    Abstract: Methods and novel intermediates for the preparation of acyclic nucleoside derivatives of the formula: 1
    Type: Application
    Filed: June 17, 2004
    Publication date: December 9, 2004
    Applicant: Medivir AB
    Inventors: M. Robert Leanna, Steven M. Hannick, Michael Rasmussen, Jien-Heh J. Tien, Lakshmi Bhagavatula, Pulla Reddy Singam, Bradley D. Gates, Lawrence Kolaczkowski, Ramesh R. Patel, Greg Wayne, Greg Lannoye, Weijiang Zhang, Zhenping Tian, Kirill A. Lukin, Bikshandarkoil A. Narayanan, David A. Riley, Howard Morton, Sou-Jen Chang, Cynthia B. Curty, Daniel Plata, John Bellettini, Bhadra Shelat, Tiffany Spitz, Cheng-Xi Yang
  • Synthesis of acyclic nucleoside derivatives
    Publication number: 20040024214
    Abstract: Methods and novel intermediates for the preparation of acyclic nucleoside derivatives of the formula: 1
    Type: Application
    Filed: December 9, 2002
    Publication date: February 5, 2004
    Applicant: Medivir AB
    Inventors: M. Robert Leanna, Michael Rasmussen, Howard Morton, Zhenping Tian, Daniel Plata, Bradley D. Gates, Bikshandarkoil A. Narayanan
  • Arylation method for the functionalization of O-allyl erythromycin derivatives
    Publication number: 20030125531
    Abstract: An efficient arylation technique for use in the synthesis of erythromycin derivatives, involving a modified Heck reaction which employs less than six mole percent of palladium catalyst and no phosphine is disclosed. With this modified Heck reaction, an O-alkenylaryl macrolide can be obtained in a much shorter reaction time than under conventional Heck reaction conditions. The modified Heck reaction can be utilized in a method for phosphine-free arylation of an O-allylic erythromycin derivative, in a method for preparing an O-alkenylaryl erythromycin A derivative, or in a method for preparing a 2′,4″-hydroxyl protected 6-O-alkenylaryl erythromycin A derivative.
    Type: Application
    Filed: May 28, 2002
    Publication date: July 3, 2003
    Inventors: Weijang Zhang, Margaret Chi-Ping Hsu, Anthony R. Haight, Matthew John Peterson, Bikshandarkoil A. Narayanan
  • Synthesis of acyclic nucleoside derivatives
    Patent number: 6184376
    Abstract: Methods and novel intermediates of the formula: wherein R6 and R7 are lower alkyl or benzyl or R6 and R7 taken together are —CH2CH2—, —CH2CH2CH2— or —CH2CH2CH2CH2CH2—, R8 is C1-C21 alkyl or a C2-C21 monounsaturated alkenyl, which may optionally be substituted with substitution substituents independently selected from the group consisting of hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkoxy C1-C6 alkyl, C1-C6 alkanoyl, amino, halo, cyano, azido, oxo, mercapto and nitro, and R9 is an alcohol protecting group. The intermediates are useful for the preparation of acyclic nucleoside derivatives of the formula: where one of R1 and R2 is an amino acid acyl group and the other of R1 and R2 is a —C(O)C3-C21 saturated or monounsaturated, optionally substituted alkyl and R3 is OH or H; or a pharmaceutically acceptable salt thereof.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: February 6, 2001
    Assignee: Mediver AB
    Inventors: M. Robert Leanna, Steven M. Hannick, Michael Rasmussen, Jien-Heh J. Tien, Lakshmi Bhagavatula, Pulla Reddy Singam, Bradley D. Gates, Lawrence Kolaczkowski, Ramesh R. Patel, Greg Wayne, Greg Lannoye, Weijiang Zhang, Zhenping Tian, Kirill A. Lukin, Bikshandarkoil A. Narayanan, David A. Riley, Howard Morton, Sou-Jen Chang, Cynthia B. Curty, Daniel Plata, John Bellettini, Bhadra Shelat, Tiffany Spitz, Cheng-Xi Yang
  • Process for reduction of (2R)-4-oxoazetidinone-2-carboxylic acid
    Patent number: 6103911
    Abstract: The present invention relates to a process for the reduction of an azetidinone-carboxylic acid to an azetidine-alcohol.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: August 15, 2000
    Assignee: Abbott Laboratories
    Inventors: James E. Resek, Shyamal I. Parekh, Pulla R. Singam, Hemant H. Patel, Michael H. Cain, Bikshandarkoil A. Narayanan
  • Process for the stereoselective production of nitro-enamine compounds
    Patent number: 5801250
    Abstract: The present invention relates to an asymmetric Michael Addition reaction to produce nitro ketone diasteroisomers with enhanced stereoselectivity.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: September 1, 1998
    Assignee: Abbott Laboratories
    Inventors: Patricia A. Oliver-Shaffer, Bikshandarkoil A. Narayanan, James E. Resek, Pulla Reddy Singam