Patents by Inventor Sandip Vasant Chikhalikar

Sandip Vasant Chikhalikar 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).

  • Process for the Preparation of an Endothelin Receptor Antagonist
    Publication number: 20140256004
    Abstract: The present invention relates to a novel process for the preparation of a compound of formula (I) wherein R is a methyl or methoxy group; to certain novel intermediates prepared in such a process and their use.
    Type: Application
    Filed: October 19, 2012
    Publication date: September 11, 2014
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Sanjay Naik, Maruti Ghagare, Sandip Vasant Chikhalikar
  • Process for the synthesis of naratriptan
    Patent number: 8735589
    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: Grant
    Filed: August 18, 2010
    Date of Patent: May 27, 2014
    Assignee: Cipla Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Sandip Vasant Chikhalikar, Maruti Ghagare
  • Processes for the synthesis of levocetirizine and intermediates for use therein
    Patent number: 8350031
    Abstract: The present invention provides a compound of formula (IV) wherein R is Cl, Br, NO2, OH or OR?, and R? is alkyl, and its use in the synthesis of levocetirizine, including its use in the synthesis of (?)-1-[(4-chlorophenyl)-phenylmethyl]piperazine, an intermediate useful in the synthesis of levocetirizine. The present invention also provides compounds (II) and (III) which are useful in the synthesis of compound (IV).
    Type: Grant
    Filed: June 2, 2009
    Date of Patent: January 8, 2013
    Assignee: CIPLA Limited
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Maruti Ghagare, Sandip Vasant Chikhalikar
  • Process for the synthesis of naratriptan
    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
  • Synthesis of 4-[1-(4-cyano phenyl)-(1,2,4-triazol-1-yl)methyl] benzonitrile and 4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile intermediate
    Patent number: 8003804
    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: Grant
    Filed: March 19, 2007
    Date of Patent: August 23, 2011
    Assignee: CIPLA Limited
    Inventors: Srinivas Laxminarayan Pathi, Rajendra Narayanrao Kankan, Dharmaraj Ramachandra Rao, Sandip Vasant Chikhalikar
  • Processes for the Synthesis of Levocetirizine and Intermediates for Use Therein
    Publication number: 20110184174
    Abstract: The present invention provides a compound of formula (IV) wherein R is Cl, Br, NO2, OH or OR?, and R? is alkyl, and its use in the synthesis of levocetirizine, including its use in the synthesis of (?)-1-[(4-chlorophenyl)-phenylmethyl]piperazine, an intermediate useful in the synthesis of levocetirizine. The present invention also provides compounds (II) and (III) which are useful in the synthesis of compound (IV).
    Type: Application
    Filed: June 2, 2009
    Publication date: July 28, 2011
    Applicant: CIPLA LIMITED
    Inventors: Dharmaraj Ramachandra Rao, Rajendra Narayanrao Kankan, Maruti Ghagare, Sandip Vasant Chikhalikar
  • Synthesis of 4-[1-(4-cyano phenyl)-(1,2,4-triazol-1-yl)methyl] benzonitrile and 4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile intermediate
    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