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).

  • Patent number: 8344149
    Abstract: Crystalline raloxifene hydrochloride in hydrated form, particularly the monohydrate, processes for its preparation, pharmaceutical compositions comprising it and uses thereof.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: January 1, 2013
    Assignee: Cipla Limited
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Patent number: 8324381
    Abstract: A process for the preparation of valganciclovir with triacetyl ganciclovir (V) as a starting material, comprising the following steps: selective hydrolysis, reacting with a coupling agent and CBZ valine and a solvent, followed by hydrolysis under basic conditions and hydrogenolysis in the presence of a catalyst.
    Type: Grant
    Filed: March 20, 2007
    Date of Patent: December 4, 2012
    Assignee: CIPLA Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Vidyadhar Purushottam Pande
  • Patent number: 8288561
    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: Grant
    Filed: May 7, 2008
    Date of Patent: October 16, 2012
    Assignee: CIPLA Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Srinivas Laxminarayan Pathi, Ravikumar Puppala
  • Patent number: 8288568
    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: Grant
    Filed: May 16, 2008
    Date of Patent: October 16, 2012
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Dilip Ramdas Birari, Manjinder Singh Phull
  • Patent number: 8269003
    Abstract: The invention relates to imatinib for use in tumor therapy. This invention describes a stable, non hygroscopic alpha crystalline form of methane sulfonic acid addition salt of 4-(4-methyl piperazin-1-yl methyl)-N-[4-methyl-3-(4-pyridin-3-yl)-pyrimidin-2-yl amino) phenyl]-benzamide (imatinib mesylate) having the general structural formula A process for the preparation of the crystalline form is also described.
    Type: Grant
    Filed: September 2, 2005
    Date of Patent: September 18, 2012
    Assignee: CIPLA Limited
    Inventors: Srinivas Laxminarayan Pathi, Revikumar Puppala, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Publication number: 20120232091
    Abstract: The invention relates to various new polymorphic forms of manidipine and pharmaceutically acceptable salts thereof. The invention also relates to processes for the preparation of the polymorphic forms of manidipine and pharmaceutically acceptable salts thereof.
    Type: Application
    Filed: August 26, 2010
    Publication date: September 13, 2012
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Maruti Ganpati Ghagare
  • Patent number: 8263787
    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 hydroxysulfone 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: Grant
    Filed: May 7, 2008
    Date of Patent: September 11, 2012
    Assignee: CIPLA Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Shrikant Suresh Mudgal
  • Patent number: 8258294
    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: Grant
    Filed: September 28, 2007
    Date of Patent: September 4, 2012
    Assignee: CIPLA Limited
    Inventors: Srinivas Laxminarayan Pathi, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Publication number: 20120220778
    Abstract: The present invention relates to a process for preparing naratriptan or a salt thereof, the process comprising: (a) reacting a compound of formula (3) with a compound of the formula HCCR wherein Z is a protecting group, Y is a leaving group and R is a trialkyl silyl group, a trialkylstannyl group or a zinc (II) halide, to obtain the compound of formula (4); (b) converting the compound of formula (4) to a compound of formula (5) wherein Z? is hydrogen or a benzyl group; (c) converting the compound of formula (5) to naratriptan; and (d) optionally converting naratriptan to a salt thereof. The present invention also provides novel compounds (3) and (4) and processes for their preparation.
    Type: Application
    Filed: August 18, 2010
    Publication date: August 30, 2012
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Sandip Vasant Chikhalikar, Maruti Ghagare
  • Patent number: 8247434
    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: November 19, 2008
    Date of Patent: August 21, 2012
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Manish Gopaldas Gangrade, Dilip Ramdas Birari
  • Patent number: 8242269
    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: Grant
    Filed: October 9, 2008
    Date of Patent: August 14, 2012
    Assignee: CIPLA Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Srinivas Laxminarayan Pathi
  • Patent number: 8236959
    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: Grant
    Filed: February 28, 2008
    Date of Patent: August 7, 2012
    Assignee: Cipla Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Dilip Birari, Ashwini Amol Sawant
  • Publication number: 20120165524
    Abstract: In an embodiment, the present invention provides a process for preparing (?)-6-(4-aminophenyl)-5-methylpyridazin-3-(2H)-one, which process comprises: a) reacting racemic 6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone of formula II with a chiral tartaric acid derivative to obtain a diastereomeric salt of (?)-6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone and the chiral tartaric acid derivative; and b) reacting the diastereomeric salt with a base to obtain (?)-6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone. The (?)-6-(4-aminophenyl)-4,5-dihydro-5-methyl-3-(2H)-pyridazinone may be used to prepare levosimendan.
    Type: Application
    Filed: July 12, 2010
    Publication date: June 28, 2012
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Manjinder Singh Phull, Ashwini Amol Sawant
  • Publication number: 20120157544
    Abstract: The present invention relates to a compound of formula A, wherein R is alkyl. Compound A may be used as an intermediate in the preparation of O-desmethyl venlafaxine or a salt thereof, and the present invention provides such a preparation, as well as a process for preparing the compound of formula A.
    Type: Application
    Filed: July 14, 2010
    Publication date: June 21, 2012
    Applicant: CIPLA LIMITED
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Manohar Raghunath Surve
  • Patent number: 8198451
    Abstract: A new polymorph of moxifloxacin hydrochloride is described, together with a method for making the polymorph.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: June 12, 2012
    Assignee: CIPLA Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Srinivas Laxminarayan Pathi, Ravikumar Puppala, Manish Gangrade, Shashirekha Kanathala
  • Patent number: 8183269
    Abstract: The present invention relates to a process for the preparation of rufinamide of formula I, which process comprises: (i) reacting a 2,6-difluorobenzylhalide of formula II, wherein X is chloride, bromide or iodide, with an azide to obtain 2-(azidomethyl)-1,3-difluorobenzene of formula III; (ii) reacting 2-(azidomethyl)-1,3-difluorobenzene of formula III with methyl propiolate to obtain methyl 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylate of formula IV; and (iii) reacting methyl 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylate of formula IV with ammonia to obtain rufinamide of formula I.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: May 22, 2012
    Assignee: CIPLA Limited
    Inventors: Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Dilip Ramdas Birari
  • Publication number: 20120116071
    Abstract: Amorphous rifaximin, methods of making it, and pharmaceutical compositions containing it. Also described are methods of converting amorphous rifaximin to crystalline rifaximin and vice versa.
    Type: Application
    Filed: January 13, 2012
    Publication date: May 10, 2012
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra RAO, Rajendra Narayanrao KANKAN, Manjinder Singh PHULL, Maruti Ghagare
  • Patent number: 8158780
    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: Grant
    Filed: September 18, 2007
    Date of Patent: April 17, 2012
    Assignee: Cipla Limited
    Inventors: Manjinder Singh Phull, Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan
  • Patent number: 8133996
    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: Grant
    Filed: February 6, 2008
    Date of Patent: March 13, 2012
    Assignee: CIPLA Limited
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao
  • Patent number: RE43844
    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: December 4, 2012
    Assignee: Cipla Limited
    Inventors: Yusuf Khwaja Hamied, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao