Patents by Inventor Rajendra Narayanrao Kankan

Rajendra Narayanrao Kankan 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: 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: 20090263333
    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. A pharmaceutical composition comprises a therapeutically effective isomer of salbutamol or a salt, solvate, ester, derivative or polymorph thereof, a glucocorticoid and a pharmaceutically acceptable carrier or excipient and optionally one or more other therapeutic agents.
    Type: Application
    Filed: December 19, 2005
    Publication date: October 22, 2009
    Inventors: Amar Lulla, Geena Malhotra, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Alka Chaudhary
  • Patent number: 7598387
    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: Grant
    Filed: May 3, 2005
    Date of Patent: October 6, 2009
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20090221830
    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: November 19, 2008
    Publication date: September 3, 2009
    Applicant: Cipla Limited
    Inventors: Dharmaraj Ramachandra RAO, Rajendra Narayanrao KANKAN, Manish Gopaldas GANGRADE, Dilip Ramdas BIRARI
  • Patent number: 7579505
    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: Grant
    Filed: December 19, 2005
    Date of Patent: August 25, 2009
    Assignee: CIPLA Limited
    Inventors: Dharmaraj Ramchandra Rao, Rajendra Narayanrao Kankan, Alka Chaudhary
  • 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
  • Patent number: 7550593
    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: Grant
    Filed: July 5, 2004
    Date of Patent: June 23, 2009
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20090137648
    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: Application
    Filed: October 26, 2005
    Publication date: May 28, 2009
    Inventors: Pathi L. Srinivas, Jayamadhava P. Relekar, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 7538249
    Abstract: Racemic tolterodine free base in crystalline form, tolterodine with improved purity, compositions and uses thereof, and processes of preparing the same.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: May 26, 2009
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20090069574
    Abstract: A process for the synthesis of trandolapril which comprises condensing N-[I-(S)-ethoxycarbonyl-3-phenylpropyl]-L-alanine N-carboxyanhydride with trans octahydro-1H-indole-2-carboxylic acid in a first organic solvent comprising a water immiscible inert organic solvent and in the presence of a base, and isolating trandolapril from a second organic solvent. N-[1-(S)-ethoxycarbonyl-3-phenylpropyl]-L-alanine N-carboxyanhydride may also be condensed with (2S,3aR,7aS) octahydro-1H-indole-2-carboxylic acid in a first organic solvent and in the presence of a base, and trandolapril isolated. There is also provided a process for the resolution of racemic trans octahydro-1H-indole-2-carboxylc acid.
    Type: Application
    Filed: July 5, 2006
    Publication date: March 12, 2009
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Manjinder Singh Phull, Ashwini Sawant, Dilip Ramdas Birari
  • Patent number: 7470789
    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: Grant
    Filed: August 25, 2004
    Date of Patent: December 30, 2008
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Manish Gopaldas Gangrade, Dilip Ramdas Birari
  • Patent number: 7439367
    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 R4 is selected from the group consisting of hydrogen or substituted or unsubstituted C1-4alkoxy.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: October 21, 2008
    Assignee: CIPLA Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Pathi L. Srinivas
  • Publication number: 20080234492
    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: Application
    Filed: May 19, 2005
    Publication date: September 25, 2008
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • 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
  • Patent number: 7351840
    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 the free acid formed by the deprotection
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: April 1, 2008
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20080070949
    Abstract: Crystalline form C of rimonabant and amorphous rimonabant, processes for their preparation and pharmaceutical compositions thereof.
    Type: Application
    Filed: April 17, 2007
    Publication date: March 20, 2008
    Applicant: Cipla Limited
    Inventors: Manjinder Singh, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 7285669
    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: Grant
    Filed: November 3, 2003
    Date of Patent: October 23, 2007
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 7112577
    Abstract: A pharmaceutically acceptable alendronate salt in an amorphous form.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: September 26, 2006
    Assignee: Cipla Limited
    Inventors: Yusuf Khwaja Hamied, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 6995286
    Abstract: A process for making optically pure (R) and (S) salbutamol comprises obtaining the (R) or (S) isomer of either salbutamol or a salbutamol precursor in substantially optically pure form by resolving a racemic or optically impure mixture of enantiomers of salbutamol or of said precursor with either (L) or (D) tartaric acid, and where necessary converting said isomer of said precursor into either (R or (S) salbutamol respectively; then optionally converting said optically pure (R) and/or (S) salbutamol into a pharmaceutically acceptable salt.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: February 7, 2006
    Assignee: Cipla Limited
    Inventors: Yusuf Khwaja Hamied, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20040259846
    Abstract: A pharmaceutically acceptable alendronate salt in an amorphous form.
    Type: Application
    Filed: July 26, 2004
    Publication date: December 23, 2004
    Inventors: Yusuf Khwaja Hamied, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan