Patents by Inventor Dharmaraj Rao

Dharmaraj Rao 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).

  • Publication number: 20080015359
    Abstract: An improved process for the preparation of telmisartan, or a pharmaceutically acceptable salt thereof, comprises subjecting 1H-Benzimidazole-2-n-propyl-4-methyl-6-(1?-methyl benzimidazole-2+yl)] of formula (II), and methyl-4-(bromomethyl)biphenyl-2-carboxylate of formula (III) to condensation and hydrolysis in a single step:
    Type: Application
    Filed: May 10, 2005
    Publication date: January 17, 2008
    Inventors: Rajendra Kankan, Dharmaraj Rao, Pathi Srinivas, Puppala Ravikumar
  • Publication number: 20070265288
    Abstract: The invention relates to a stable, non hygroscopic alpha crystalline form of methane sulfonic acid addition salt of 4-(4-methyl piperazin-1yl methyl)-N-[4-methyl-3-(4-pyridin-3-yl) pyrimidin-2-yl amino)phenyl]-benzamide (imatinib mesylate). A process for the preparation of the crystalline form is also described.
    Type: Application
    Filed: September 2, 2005
    Publication date: November 15, 2007
    Inventors: Srinivas Pathi, Ravikumar Puppala, Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20070259955
    Abstract: A one-pot process for the preparation of nateglinide, which process comprises reacting an alkyl ester of D-phenylalanine of formula (II): where R represents C1-4alkyl, typically methyl, either as the free base or in salt form (typically the hydrochloride), with trans-4-isopropylcyclohexanecarboxylic acid of formula (III): where X represents hydroxy or halo, typically chloro, to obtain a C1-4 alkyl ester of nateglinide of formula (IV), preferably the methyl ester of nateglinide: followed by hydrolysis to yield nateglinide of formula (I):
    Type: Application
    Filed: June 8, 2005
    Publication date: November 8, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao, Manjinder Singh, Dilip Birari
  • Publication number: 20070191611
    Abstract: A process of preparing rosiglitazone, or a pharmaceutically acceptable salt thereof, which process employs an intermediate metabisulphite complex of 4-[2-(N-methyl-N-(2-pyridyl)amino) ethoxy] benzaldehyde, which metabisulphite complex is represented by following formula (III); where X represents an alkali metal. The present invention further provides rosiglitazone, or a pharmaceutically acceptable salt thereof, prepared by the above process.
    Type: Application
    Filed: May 3, 2005
    Publication date: August 16, 2007
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Rao, Rajendra Kankan
  • Publication number: 20070191399
    Abstract: A process for making zaleplon comprising alkylating 3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-acetamide with ethyl iodide in the presence of an alkali metal hydroxide or alkoxide selected from sodium hydroxide, potassium hydroxide, sodium methoxide, sodium tert-butoxide or potassium tert-butoxide in an aprotic solvent to give N-ethyl-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-acetamide, condensing N-ethyl-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-acetamide and 3-amino-4-cyanopyrazole, and isolating zaleplon from the reaction. Preferably, the condensing is done in the presence of (a) a water immiscible organic acid; (b) a cation exchange resin; or (c) a water miscible organic acid in water or in a C-1 to C-4 alcohol or in a mixture of water and a C-1 to C-4 alcohol.
    Type: Application
    Filed: September 2, 2004
    Publication date: August 16, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20070191428
    Abstract: Anhydrous crystalline fexofenadine hydrochloride Form C, crystalline fexofenadine acetate monohydrate Form D, crystalline fexofenadine acetate dihydrate Form E and crystalline fexofenadine free base monohydrate Form F, processes of preparing the same, pharmaceutical compositions thereof, therapeutic uses thereof and methods of treatment therewith.
    Type: Application
    Filed: August 25, 2004
    Publication date: August 16, 2007
    Inventors: Dharmaraj Rao, Rajendra Kankan, Manish Gangrade, Dilip Birari
  • Publication number: 20070185335
    Abstract: A process for preparing perindopril (III) or a pharmaceutically acceptable salt thereof, which process comprises a substituted benzyl ester of (2S,3aS,7aS)-octahydroindole-2-carboxylic acid (I) with N-[(S)-carbethoxybutyl]-(S)-alanine (II) where R represents a halo, C1-4 alkoxy or nitro substituent.
    Type: Application
    Filed: April 7, 2005
    Publication date: August 9, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20070167513
    Abstract: The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof
    Type: Application
    Filed: May 11, 2005
    Publication date: July 19, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao, Pathi Srinivas, Puppala Ravikumar
  • Publication number: 20070142479
    Abstract: Racemic tolterodine free base in crystalline form, tolterodine with improved purity, compositions and uses thereof, and processes of preparing the same.
    Type: Application
    Filed: December 23, 2004
    Publication date: June 21, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20070135524
    Abstract: The present invention is directed to Form II, III, IV and V of sertraline hydrochloride and methods for its preparation. According to the present invention, the various polymorphs of sertraline hydrochloride may be produced either, directly from sertraline base or sertraline acetate.
    Type: Application
    Filed: November 4, 2004
    Publication date: June 14, 2007
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Rao, Rajendra Kankan
  • Publication number: 20070105885
    Abstract: The invention relates to a novel crystalline form of topotecan hydrochloride, and methods of making the same. The characteristic XRPD pattern and FT-IT patterns are shown in FIGS. 1 and 2.
    Type: Application
    Filed: October 10, 2006
    Publication date: May 10, 2007
    Applicant: Cipla Limited
    Inventors: Srinivas Pathi, Shashi Kanathala, Manish Gangrade, Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20070021455
    Abstract: A process of preparing finasteride Form (I), which process comprises dissolving finasteride in a solvent, replacing the solvent partially or substantially completely with a nonsolvent and thereafter isolating finasteride Form (I). There is also provided finasteride Form (I) prepared in accordance with the present invention, and the therapeutic use thereof in the inhibition of 5-alpha reductase, and pharmaceutical compositions containing the same.
    Type: Application
    Filed: July 5, 2004
    Publication date: January 25, 2007
    Inventors: Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20060264639
    Abstract: The present invention relates to processes for the preparation of rosiglitazone, rosiglitazone prepared thereby and pharmaceutical compositions and therapeutic uses thereof, and methods of treatment employing the same.
    Type: Application
    Filed: August 13, 2004
    Publication date: November 23, 2006
    Applicant: Cipla Limited
    Inventors: Rajendra Kankan, Dharmaraj Rao, Manjinder Phull, Dilip Birari
  • Publication number: 20060241191
    Abstract: The invention provides three polymorphic forms of crystalline levosalbutamol sulphate designated herein as Forms I, II and III. Crystalline levosalbutamol sulphate Form I is characterised by a powder XRD pattern with peaks at 10.8, 11.9, 13.0, 18.3, 28.5±0.2 degrees 2 theta. Crystalline levosalbutamol sulphate Form II is characterised by a powder XRD pattern with peaks at 8.7, 9.6, 15.2, 15.7, 19.1, 27.2, 30.7±0.2 degrees 2 theta. Crystalline levosalbutamol sulphate Form III is characterised by a powder XRD pattern with peaks at 5.5, 6.9, 7.3, 18.7±0.2 degrees 2 theta. Processes for making the new polymorphic forms and pharmaceutical compositions comprising them are also provided.
    Type: Application
    Filed: December 19, 2005
    Publication date: October 26, 2006
    Inventors: Dharmaraj Rao, Rajendra Kankan, Alka Chaudhary
  • Publication number: 20060205791
    Abstract: The present invention relates to an improved process for the preparation of a sulfinyl compound of formula (I), or a pharmaceutically acceptable salt, hydrate or solvate thereof, from a sulfide compound of formula (II), wherein in both formulae (I) and (II) R1 and R3 are selected from the group consisting of hydrogen, methyl or C1-4alkoxy, R2 is selected from the group consisting of substituted or unsubstituted C1-4alkoxy and R2 is selected from the group consisting of hydrogen or substituted or unsubstituted C1-4alkoxy.
    Type: Application
    Filed: January 12, 2004
    Publication date: September 14, 2006
    Inventors: Rajendra Kankan, Dharmaraj Rao, Pathi Srinivas
  • Publication number: 20060173182
    Abstract: A process of preparing imatinib, either as the free base or as an acid addition salt, which process comprises reacting N-(2-methyl-5-aminophenyl-4-(3-pyridyl)-2-pyrimidine amine of formula (II) with a 4-(4-methyl-piperazino methyl)benzoyl halide of formula (III) in the presence of an inert organic solvent, so as to yield a hydrohalide salt of imatinib formula (I) where n represents 1, 2 or 3 and Hal represents bromo, chloro, fluoro or iodo, either in anhydrous or hydrated form, which can as desired optionally be further converted either to the free base or a further acid addition salt. The present invention is also concerned with imatinib prepared according to the above process.
    Type: Application
    Filed: January 8, 2004
    Publication date: August 3, 2006
    Applicant: CIPLA Limited
    Inventors: Rajendra Kankan, Dharmaraj Rao
  • Publication number: 20060100256
    Abstract: 2,6-diamino-4,5,6,7-tetrahydro-benzothiazole, which is useful for making pramipexole, is made by: (i) reacting bromine with a solution of 4-acetamido-cyclohexanone in water to produce 2-bromo-4-acetamido-cyclohexanone; (ii) after step (i), adding thiourea to produce 6-acetyl amino-2-amino-4,5,6,7-tetrahydro-benzthiazole; (iii) after step (ii), adding an aqueous solution of hydrobromic acid to produce 2,6-diamino-4,5,6,7-tetrahydro-benzthiazole dihydrobromide; and (iv) after step (iii), isolating 2,6-diamino-4,5,6,7-tetrahydro-benzthiazole.
    Type: Application
    Filed: November 3, 2003
    Publication date: May 11, 2006
    Inventors: Dharmaraj Rao, Rajendra Kankan
  • Publication number: 20060063941
    Abstract: A pharmaceutically acceptable salt of perindopril of formula (I) is made from a protected precursor compound of formula (II) wherein R represents a carboxyl protecting group, which process comprises subjecting a compound of formula (II) to deprotection of the carboxylic group COOR attached to the heterocyclic ring so as to yield the corresponding free acid, which deprotection is carried out in the presence of a base which forms a pharmaceutically acceptable salt with said free acid formed by said deprotection.
    Type: Application
    Filed: November 18, 2003
    Publication date: March 23, 2006
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Rao, Rajendra Kankan