Patents by Inventor Dharmaraj Ramachandra Rao

Dharmaraj Ramachandra 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: 20110034477
    Abstract: Crystalline Form IV of doxazosin mesylate, a process for its preparation and uses thereof.
    Type: Application
    Filed: July 10, 2008
    Publication date: February 10, 2011
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Manish Gopaldas Gangrade, Shrikant Suresh Mudgal
  • Publication number: 20110015394
    Abstract: The present invention relates to alkaline earth metal salts of bosentan, anyhdrous bosentan, polymorphic forms thereof, amorphous bosentan and processes for preparing them. The present invention further relates to a process for the preparation of bosentan and its pharmaceutically acceptable salts.
    Type: Application
    Filed: January 2, 2009
    Publication date: January 20, 2011
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Manjinder Singh Phull, Ashwini Amol Sawant
  • 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: 20100311980
    Abstract: There is provided a process for preparing sorafenib or a salt thereof comprising the use of a compound of formula (A) wherein R? is selected from the group consisting of hydrogen, —C(O)OA, —C(O)CX3, —C(O)NH2, —C(O)—NHOH or There is also provided intermediate compounds of general formula (A), N-methyl-4-(4-ureidophenoxy)picolinamide, 4-(2-(methylcarbamoyl)pyridin-4-yloxy)phenylcarbamate derivative and N-methyl-4-(4-(2,2,2-trihaloacetamido)phenoxy)picolinamide, processes for their preparation and their use in the preparation of sorafenib.
    Type: Application
    Filed: September 10, 2008
    Publication date: December 9, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Maruti Ghagare, Sandip Chikhalikar
  • 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
  • Publication number: 20100256370
    Abstract: A process for preparing alfuzosin or a salt thereof comprising: (a) condensing 4-amino-2-chloro-6,7-dimethoxyquinazoline with 3-methylaminopropionitrile in the presence of a polar aprotic solvent selected from the group consisting of diglyme, dimethyl formamide, t-butanol, hexamethylphosphoramide or mixtures thereof to form N-(4-amino-6,7-dimethoxyquinazol-2-yl)-N-methyl-2-cyanoethylamine (b) hydrogenating the N-(4-amino-6,7-dimethoxyquinazol-2-yl)-N-methyl-2-cyanoethylamine using a hydrogenating agent under a pressure of less than 10 kg/cm2 to form N-(4-amino-6,7-dimethoxyquinazol-2-yl)-N-methylpropylenediamine and optionally converting the N-(4-amino-6,7-dimethoxyquinazol-2-yl)-N-methylpropylenediamine to an acid addition salt thereof; and (c) converting tetrahydrofuroic acid to an intermediate form and condensing the intermediate form with the N-(4-amino-6,7-dimethoxyquinazol-2-yl)-N-methylpropylenediamine or with the acid addition salt to yield alfuzosin base, and optionally converting alfuzosin base to a
    Type: Application
    Filed: August 1, 2008
    Publication date: October 7, 2010
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Dilip Birari
  • 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: 20100222572
    Abstract: Improved processes for the synthesis of ciclesonide, chemically termed as [11?,16?(R)]-16,17-[(cyclohexylmethylene)bis(oxy)]-11-hydroxy-21-(2-methyl-1-oxopropoxy)pregna-1,4-diene-3,20-dione and its crystal modification.
    Type: Application
    Filed: September 18, 2007
    Publication date: September 2, 2010
    Applicant: CIPLA LIMITED
    Inventors: Manjinder Singh Phull, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20100204493
    Abstract: The present invention provides a novel process for the preparation of a compound of Formula III, and novel processes for preparing escitalopram using the compound of Formula III.
    Type: Application
    Filed: May 16, 2008
    Publication date: August 12, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Dilip Ramdas Birari, Manjinder Singh Phull
  • Patent number: 7772394
    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: Grant
    Filed: September 2, 2004
    Date of Patent: August 10, 2010
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • 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: 20100113790
    Abstract: A process for preparing a compound of formula (III) comprising condensing an oxiranyl compound of formula (I) with an amine of formula (II) or a salt thereof wherein: R1 is a group selected from alkyl, aryl, allyl, alkoxy, cycloalkyl, heterocyclic, alkenyl, benzocycloalkyl, aralkyl, haloarylalkyl, heteroaralkyl, haloalkyl, alkoxyaralkyl, substituted silyl and benzyl; and R2 is hydrogen, optionally substituted silyl or optionally substituted benzyl. There is also described a process for preparing (R,R)-carmoterol from compound (III).
    Type: Application
    Filed: February 28, 2008
    Publication date: May 6, 2010
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Dilip Birari, Ashwini Amol Sawant
  • Publication number: 20100113804
    Abstract: There is provided a process for preparing dorzolamide and processes for preparing intermediates useful in the preparation of dorzolamide. In particular, there is provided a process for preparing an acetoamido sulfone of formula (viii) comprising oxidation of a hydroxysulfonamide of formula (vii) in the presence of an oxidizing agent selected from the group consisting of: a peracid, tert-butyl hydroperoxide, dimethyl dioxirane, selenium dioxide, m-phenanthroline di-N-oxide, nitric acid and hydrogen peroxide. There is also provided a process for preparing an acetoamidosulfone of formula (ix-a) comprising converting a hydroxy sulfone of formula (viii) to the acetoamidosulfone of formula (ix-a) in the presence of acetonitrile and an acid. There is also provided a process for separating the cis- and trans-isomers of dorzolamide from a mixture of the trans-isomer of dorzolamide and the cis-isomer of dorzolamide comprising reacting the mixture of isomers with a carboxylic acid.
    Type: Application
    Filed: May 7, 2008
    Publication date: May 6, 2010
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Shrikant Suresh Mudgal
  • 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
  • Patent number: 7705163
    Abstract: A process for the preparation of carvedilol of formula (I) (I) either in enantiomeric substantially pure form, or as an enantiomeric mixture, optionally as a pharmaceutically acceptable salt thereof, which process comprises reacting 2,3-eopxypropoxy carbazole of formula (II) (II) or the R or S enantiomer thereof, with N-[2-(2-methoxy-phenoxy)ethyl]-benzylamine of formula (V) (V) to yield benzyl carvedilol of formula (VI) (VI) which is debenzylated by catalytic hydrogenation to yield carvedilol of formula (I), either in enantiomeric substantially pure form, or as an enantiomeric mixture, and if desired reacting the thus formed carvedilol of formula (I) with an inorganic or organic acid to yield a pharmaceutically acceptable salt thereof, and/or, if desired, separating the enantiomers. The above process is characterised in that reaction of said 2,3-epoxypropoxy carbazole of formula (II) with said N-[2-(2-methoxy-phenoxy)ethyl]-benzylamine of formula (V) is carried out in water as the reaction medium.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: April 27, 2010
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • 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: 20100094004
    Abstract: A process for the preparation of a salt of N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine comprising reacting a 4˜halo-6,7-bis(2-methoxyethoxy) quinazoline with 3-aminophenyl acetylene or an acid salt thereof under acidic conditions to form the corresponding acid salt of N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine, the process optionally further comprising converting the acid salt of N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine to N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine.
    Type: Application
    Filed: April 3, 2008
    Publication date: April 15, 2010
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • 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