Patents by Inventor Srinivas Laxminarayan Pathi

Srinivas Laxminarayan Pathi 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: 7989636
    Abstract: A process for the preparation of anastrozole which comprises: a) brominating 3,5-bis(2-cyanoprop-2-yl)toluene (II) in an organic solvent using a brominating agent to obtain 3,5-bis(2-cyanoprop-2-yl)benzylbromide (III); b) heating the reaction mass of step a) to the reflux temperature of the organic solvent for a period of time no longer than 3 hours; c) isolating and purifying the bromo intermediate (III) using an organic solvent; d) alkylating the bromo intermediate in the presence of a base, optionally a phase transfer catalyst, a 1,2,4-triazole and an organic solvent to obtain anastrozole; and e) isolating and purifying the anastrozole from an organic solvent.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: August 2, 2011
    Assignee: Cipla Limited
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Patent number: 7951837
    Abstract: The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: May 31, 2011
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Srinivas Laxminarayan Pathi, Revikumar Puppala
  • Publication number: 20110105763
    Abstract: An N-[(2?-(1-triphenyl methyl tetrazole-5-yl)biphenyl]-4-yl]methyl]-L-valine benzyl ester organic salt of formula (IVA) wherein A represents an organic carboxylic acid, a process for its preparation and its use in the synthesis of valsartan or salts thereof.
    Type: Application
    Filed: May 7, 2008
    Publication date: May 5, 2011
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Srinivas Laxminarayan Pathi, Ravikumar Puppala
  • Publication number: 20110077271
    Abstract: The present invention provides a process for preparing donepezil or a salt thereof, the process comprising reducing a 1-benzyl-4-[(5,6-dimethoxy-1-indanon-2-yl)methylene]pyridonium halide of formula II, wherein X is bromide or chloride, in the presence of an ionic compound, a solvent, a catalyst and a source of hydrogen, to form donepezil and optionally converting the donepezil to the salt thereof.
    Type: Application
    Filed: March 24, 2009
    Publication date: March 31, 2011
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi
  • Publication number: 20110009450
    Abstract: Crystalline raloxifene hydrochloride in hydrated form, particularly the monohydrate, processes for its preparation, pharmaceutical compositions comprising it and uses thereof.
    Type: Application
    Filed: October 17, 2007
    Publication date: January 13, 2011
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanro Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20100298565
    Abstract: The present invention relates to novel compounds of formula (VIII) and (X), processes for their preparation and their use in the preparation of paliperidone or a salt thereof. There is also provided by the present invention novel processes for preparing intermediates for use in the preparation of paliperidone or a salt thereof, and novel processes for preparing paliperidone or a salt thereof.
    Type: Application
    Filed: October 9, 2008
    Publication date: November 25, 2010
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Srinivas Laxminarayan Pathi
  • Patent number: 7799928
    Abstract: The present invention is concerned with a process for the preparation of 2n-butyl-4-spirocyclopentane-1-[(2?-(tetrazol-5-yl)biphenyl-4-yl)methyl]-2-imidazolin-5-one hydrochloride, irbesartan hydrochloride, novel hydrated and anhydrous crystalline forms thereof, amorphous irbesartan hydrochloride, formulations containing the same, therapeutic uses thereof and methods of treatment employing the same. The process of the present invention is a one-pot process which comprises reacting intermediate compounds 2n-butyl-1,3-diazaspiro[4,4]non-1-en-4-one and 5-(4?-bromomethyl-biphenyl-2-yl)-1-trityl-1H-tetrazole.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: September 21, 2010
    Assignee: Cipla Limited
    Inventors: Srinivas Laxminarayan Pathi, Jayamadhava P. Relekar, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20100160643
    Abstract: A process for the preparation of trityl olmesartan comprising (a) condensing 4-(1-hydroxy-1-methylethyl)-2-propyl-imidazol-5-carboxylic acid alkyl ester with trityl biphenyl bromide in the presence of a polar aprotic solvent and a base selected from the group consisting of alkali metal carbonates, alkali metal hydroxides, alkali metal alkoxides, and tertiary amines to obtain a compound of formula V, b) deesterifying the compound of formula (V) with a base; and c) reacting the product of step (b) with 4-halomethyl-5-methyl-2-oxo-1,3-dioxolene of formula (IV), wherein X is halogen selected from F or Cl or Br or I, to obtain trityl olmesartan medoxomil of formula. The trityl olmesartan medoxomil may be deprotected to produce olmesartan medoxomil.
    Type: Application
    Filed: October 9, 2007
    Publication date: June 24, 2010
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Revikumar Puppala, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20100152229
    Abstract: A new polymorph of moxifloxacin hydrochloride is described, together with a method for making the polymorph.
    Type: Application
    Filed: November 13, 2007
    Publication date: June 17, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi, Ravikumar Puppala, Manish Gangrade, Shashirekha Kanathala
  • Publication number: 20100137586
    Abstract: There is provided a compound of formula (III), and a process for preparing a compound of formula (V) comprising converting a compound of formula (III) to the compound (V), wherein (X) is fluoro, chloro, bromo or iodo. There is also provided a process for preparing a compound of formula (XI) comprising converting a compound of formula (X) to the compound (XI). The compounds (V) and (XI) so prepared may be used in a process for preparing gefitinib.
    Type: Application
    Filed: April 16, 2008
    Publication date: June 3, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi
  • Publication number: 20100113526
    Abstract: A process for preparing Form A of (S)-5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl]sulfinyl]-1H-benzimidazole magnesium dihydrate, processes for preparing various intermediates useful in the preparation of Form A of (S)-5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl]sulfinyl]-1H-benzimidazole magnesium dihydrate and a novel polymorphic Form II of 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl]thio]-1H-benzimidazole.
    Type: Application
    Filed: February 21, 2008
    Publication date: May 6, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi, Gopalakrishna Sumana Bangalore
  • Publication number: 20100099887
    Abstract: A process for the preparation of anastrozole which comprises: a) brominating 3,5-bis(2-cyanoprop-2-yl)toluene (II) in an organic solvent using a brominating agent to obtain 3,5-bis(2-cyanoprop-2-yl)benzylbromide (III); b) heating the reaction mass of step a) to the reflux temperature of the organic solvent for a period of time no longer than 3 hours; c) isolating and purifying the bromo intermediate (III) using an organic solvent; d) alkylating the bromo intermediate in the presence of a base, optionally a phase transfer catalyst, a 1,2,4-triazole and an organic solvent to obtain anastrozole; and e) isolating and purifying the anastrozole from an organic solvent.
    Type: Application
    Filed: October 17, 2007
    Publication date: April 22, 2010
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20100081688
    Abstract: The invention relates to processes for making montelukast and to intermediates for use in the process, in particular compounds of formulas 2-7: L=OAc, OTs, OTf5OMs; where X=Cl, Br, I.
    Type: Application
    Filed: September 14, 2007
    Publication date: April 1, 2010
    Applicant: CIPLA LIMITED
    Inventor: Srinivas Laxminarayan Pathi
  • Publication number: 20100075999
    Abstract: The invention relates to a process for the preparation of anagrelide, and for the preparation of intermediates for use in preparing anagrelide. The invention also relates to the intermediates per se, in particular compounds of Formula (V): where R constitutes a suitable leaving group, which may not be hydrogen. The R group may be selected from: (i) —SiR13, (ii) —CH2Ar, (iii) —COOR2, and (iv) sulfonates such as —SO2R3.
    Type: Application
    Filed: February 6, 2008
    Publication date: March 25, 2010
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20100016605
    Abstract: A one-pot process for the preparation of pantoprazole sodium by reacting 2-chloro methyl 3,4-dimethoxy pyridine hydrochloride with 2-mercapto-5-difluoromethoxy benzimidazole in an organic solvent system in presence of a phase transfer catalyst and further treating with aqueous sodium hypohalite solution comprising sodium hydroxide to obtain pantoprazole sodium in high yield and purity. The process for conversion of pantoprazole sodium to pantoprazole sodium sesquihydrate and also pantoprazole sodium monohydrate are also disclosed herein.
    Type: Application
    Filed: December 15, 2005
    Publication date: January 21, 2010
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi
  • Publication number: 20090326028
    Abstract: A process for the preparation of compounds of formula IA, where R?CH3 (i.e. temozolomide): comprising diazotizing a compound of the formula IIA: where in R is as defined above in the presence of at least one metal halide, an acid and a source of nitrous acid, followed by conversion of acidic solution containing temozolomide. The conversion can be carried out by a liquid-liquid extraction technique in a water immiscible solvent. The temozolomide may be further purified in an acetone-water mixture.
    Type: Application
    Filed: September 28, 2007
    Publication date: December 31, 2009
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 7638633
    Abstract: A process for preparation of rabeprazole sodium comprising oxidation of wet or dry rabeprazole sulphide with sodium hypohalite in water or a mixture of water and water miscible solvent using alkali metal hydroxide and catalyst is disclosed herein. The present invention also discloses process for preparation of rabeprazole sulphide.
    Type: Grant
    Filed: February 21, 2006
    Date of Patent: December 29, 2009
    Assignee: Cipla Limited
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20090270633
    Abstract: The present invention relates to a process for the preparation of 4-[1-(4-cyano phenyl)-1-(1,2,4-triazol-1-yl)methyl]benzonitrile (letrozole), substantially free from its isomeric impurity. The preparation involves reaction of 4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile with 4-fluorobenzonitrile in the presence of an organic solvent and a silicon amine. The present invention also relates to a process for the preparation of 4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile which involves: (a) the reaction of a 4-halomethyl benzonitrile with 1,2,4-triazole in the presence of cesium carbonate and an organic solvent to obtain a reaction mass comprising 4-[1-(1,2,4-triazole-1-yl)methyl]benzonitrile of formula II; and (b) precipitation of 4-[1-(1,2,4-triazole-1-yl)methyl]benzonitrile (II) from the reaction mass using a suitable organic solvent.
    Type: Application
    Filed: March 19, 2007
    Publication date: October 29, 2009
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Sandip Vasant Chikhalikar
  • Publication number: 20090187020
    Abstract: The invention relates to new compounds of formula (III): wherein R is a C1-C4 linear or branched alkyl group. The invention also relates to new compounds of formula (IV) wherein M is a metal. The invention also relates to methods of making compounds of formulas (III) and (IV) and to methods of making donepezil and pharmaceutically acceptable salts thereof, such as donepezil hydrochloride, using the compounds.
    Type: Application
    Filed: January 3, 2007
    Publication date: July 23, 2009
    Applicant: CIPLA LIMITED
    Inventors: Srinivas Laxminarayan Pathi, Vinod Acharya, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20080161579
    Abstract: A process for preparation of rabeprazole sodium comprising oxidation of wet or dry rabeprazole sulphide with sodium hypohalite in water or a mixture of water and water miscible solvent using alkali metal hydroxide and catalyst is disclosed herein. The present invention also discloses process for preparation of rabeprazole sulphide.
    Type: Application
    Filed: February 21, 2006
    Publication date: July 3, 2008
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao