Patents by Inventor Purna Chandra Ray

Purna Chandra Ray 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: 8247568
    Abstract: The present invention relates to a process for the preparation of pure Rabeprazole sulfoxide using the solvent mixture for the extraction steps and this invention further relates to the process for the preparation of amorphous Rabeprazole sodium using pure rabeprazole base in presence of aqueous NaOH and water miscible solvent and adding an anti-solvent.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: August 21, 2012
    Assignee: Matrix Laboratories Ltd
    Inventors: Om Dutt Tyagi, Purna Chandra Ray, Madhuresh Kumar Sethi, Bhausaheb Chavhan
  • Patent number: 8048904
    Abstract: The present invention provides a process for the preparation of Olmesartan medoxomil by condensing the ethyl 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate with 4-[2-(trityl tetrazol-5-yl)phenyl]benzyl bromide to obtain ethyl 4-(1-hydroxy-1-methyl ethyl)-2-propyl-1-{4-[2-(trityl tetrazol-5-yl)phenyl]phenyl}methylimidazole-5-carboxylate and then hydrolyzing ethyl 4-(1-hydroxy-1-methyl ethyl)-2-propyl-1-{4-[2-(trityl tetrazol-5-yl)phenyl]phenyl}methyl imidazole-5-carboxylate to obtain trityl Olmesartan dihydrate followed by reacting trityl Olmesartan dihydrate with 4-chloromethyl-5-methyl-2-oxo-1,3-dioxolene to obtain trityl Olmesartan medoxomil and then deprotecting trityl Olmesartan medoxomil to obtain Olmesartan medoxomil.
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: November 1, 2011
    Assignee: Matrix Laboratories Ltd.
    Inventors: Gorantla Seeta Ramanjaneyulu, Bandari Mohan, Purna Chandra Ray, Madhuresh Kumar Sethi, Vijendra Singh Rawat, Yerramalla Raja Krishna, Vemula Lakshminarayana, Mamidi Srinivas
  • Patent number: 8026356
    Abstract: The present invention provides a method for preparing pure Stavudine having purity more than 99.5% comprises: i) Converting 3?,5?-anhydrothymidine to crude Stavudine, ii) Converting crude Stavudine to stable solvates of Stavudine, iii) Desolvation of the solvates to give pure Stavudine. The present invention also disclosed novel solvates of Stavudine and conversion of novel Stavudine solvates to Stavudine.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: September 27, 2011
    Assignee: Matrix Laboratories, Ltd.
    Inventors: Purna Chandra Ray, Jagan Mohana Chary Tummanapalli, Seeta Ramanjaneyulu Gorantla
  • Publication number: 20100190989
    Abstract: The present invention relates to a process for the preparation of pure Rabeprazole sulfoxide using the solvent mixture for the extraction steps and this invention further relates to the process for the preparation of amorphous Rabeprazole sodium using pure rabeprazole base in presence of aqueous NaOH and water miscible solvent and adding an anti-solvent.
    Type: Application
    Filed: June 19, 2008
    Publication date: July 29, 2010
    Applicant: MATRIX LABORATORIES LTD
    Inventors: Om Dutt Tyagi, Purna Chandra Ray, Madhuresh Kumar Sethi, Bhausaheb Chavhan
  • Publication number: 20090281327
    Abstract: The present invention provides a process for the preparation of Olmesartan medoxomil] by condensing the ethyl 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylate with 4-[2-(trityl tetrazol-5-yl)phenyl]benzyl bromide to obtain ethyl 4-(1-hydroxy-1-methyl ethyl)-2-propyl-1-{4-[2-(trityl tetrazol-5-yl)phenyl]phenyl}methylimidazole-5-carboxylate and then hydrolyzing ethyl 4-(1-hydroxy-1-methyl ethyl)-2-propyl-1-{4-[2-(trityl tetrazol-5-yl)phenyl]phenyl}methyl imidazole-5-carboxylate to obtain trityl Olmesartan dihydrate followed by reacting trityl Olmesartan dihydrate with 4-chloromethyl-5-methyl-2-oxo-1,3-dioxolene to obtain trityl Olmesartan medoxomil and then deprotecting trityl Olmesartan medoxomil to obtain Olmesartan medoxomil.
    Type: Application
    Filed: June 15, 2007
    Publication date: November 12, 2009
    Inventors: Gorantla Seeta Ramanjaneyulu, Bandari Mohan, Purna Chandra Ray, Madhuresh Kumar Sethi, Vijendra Singh Rawat, Yerramalla Raja Krishna, Vemula Lakshminarayana, Mamidi Srinivas
  • Publication number: 20090062550
    Abstract: The present invention provides a method for preparing pure Rizatriptan benzoate having purity more than 99.5% and dimer impurity less than 0.1% comprises, i) Condensation of 1,2,4-Triazole with 4-Nitro benzyl bromide to yield 1-(4-nitrophenyl)methyl-1,2,4-triazole ii) Reducing the 1-(4-nitrophenyl)methyl-1,2,4-triazole to give 1-(4-aminophenyl)methyl-1,2,4-triazole iii) Converting 1-(4-aminophenyl)methyl-1,2,4-triazole to 1-(4-hydrazinophenyl)methyl-1,2,4-triazole hydrochloride iv) Condensing the hydrazine derivative with 4-(Dimethylamino) butanal diethylacetal to get Rizatriptan and v) Salification of Rizatriptan to Rizatriptan benzoate.
    Type: Application
    Filed: November 14, 2006
    Publication date: March 5, 2009
    Applicant: MATRIX LABORATORIES LTD
    Inventors: Purna Chandra Ray, Mohan Bandari, Mohammed Qadeeruddin, Seeta Ramanjaneyulu Gorantla
  • Publication number: 20080312428
    Abstract: The present invention provides a method for preparing pure Stavudine having purity more than 99.5% comprises: i) Converting 3?,5?-anhydrothymidine to crude Stavudine, ii) Converting crude Stavudine to stable solvates of Stavudine, iii) Desolvation of the solvates to give pure Stavudine. The present invention also disclosed novel solvates of Stavudine and conversion of novel Stavudine solvates to Stavudine.
    Type: Application
    Filed: November 17, 2006
    Publication date: December 18, 2008
    Applicant: MATRIX LABORATORIES LTD
    Inventors: Purna Chandra Ray, Jagan Mohana Chary Tummanapalli, Seeta Ramanjaneyulu Gorantla
  • Patent number: 7148355
    Abstract: The present invention relates to a cost effective and industrially advantageous process for the preparation of repaglinide.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: December 12, 2006
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Purna Chandra Ray, Jayachandra Suresh Babu, Mohammad Salman, Naresh Kumar
  • Patent number: 7078524
    Abstract: The present invention relates to an industrial useful process for the synthesis of antiviral compound, ganciclovir which comprises dissolving a mixture containing N-7 and N-9 isomers of structural formulae, II and III, respectively: in a solvent or a mixture of solvents; separating the N-7 and N-9 isomers; and hydrolizing the N-9 isomer to obtain ganciclovir.
    Type: Grant
    Filed: November 22, 2002
    Date of Patent: July 18, 2006
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Jayachandra Suresh Babu, Purna Chandra Ray, Yatendra Kumar, Chandra Has Khanduri
  • Publication number: 20050176956
    Abstract: The present invention relates to an improved process for the preparation of N2-acetyl-9-(1,3-diacetoxy-2-propoxymethyl)guanine, referred to here as the N-9 alkylated isomer, useful as intermediate for the preparation of antiviral compound, ganciclovir, including addition of a monoacetyl guanine, and optionally, addition of N2-acetyl-9-(1,3-diacetoxy-2-propoxymethyl)guanine, referred to herein as the N-7 alkylated isomer.
    Type: Application
    Filed: October 15, 2002
    Publication date: August 11, 2005
    Inventors: Jayachandra Babu, Purna Chandra Ray, Chandra Khanduri, Yatendra Kumar
  • Publication number: 20040102628
    Abstract: The present invention relates to an industrial useful process for the synthesis of antiviral compound, ganciclovir.
    Type: Application
    Filed: November 22, 2002
    Publication date: May 27, 2004
    Inventors: Jayachandra Suresh Babu, Purna Chandra Ray, Yatendra Kumar, Chandra Has Khanduri
  • Patent number: 5696275
    Abstract: A process for the manufacture of pharmaceutical grade ranitidine base(N-?2-???5-(Dimethylamino)methyl!-2-furanyl!methyl!thio!ethyl-N'-methy l-2-nitro-1, 1-ethenediamine), is described. In-vitro and in-vivo pharmacological studies and acute toxicity studies indicate that it is as active and as safe as Form 2 ranitidine hydrochloride.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: December 9, 1997
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Jag Mohan Khanna, Naresh Kumar, Brij Khera, Purna Chandra Ray