The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 2015
Filed:
Jun. 24, 2011
Raveendra Reddy Chinta, Hyderabad, IN;
Gangadhara Bhima Shankar Nangi, Hyderabad, IN;
Mahendar Reddy Nayini, Hyderabad, IN;
Somappa Somannavar Yallapa, Hyderabad, IN;
Shankar Reddy Budidet, Hyderabad, IN;
Islam Aminul, Hyderabad, IN;
Sivakumaran Meenakshisunderam, Hyderabad, IN;
Raveendra Reddy Chinta, Hyderabad, IN;
Gangadhara Bhima Shankar Nangi, Hyderabad, IN;
Mahendar Reddy Nayini, Hyderabad, IN;
Somappa Somannavar Yallapa, Hyderabad, IN;
Shankar Reddy Budidet, Hyderabad, IN;
Islam Aminul, Hyderabad, IN;
Sivakumaran Meenakshisunderam, Hyderabad, IN;
Aurobindo Pharma Ltd, Hyderabad, IN;
Abstract
The present invention relates to a process for the preparation of pure Valsartan (I) substantially free from impurities of formulae (Ia), (Ib), and (Ic), which comprises: (i) condensing 2-(4'-bromomethylphenyl)benzonitrile of formula (II) with L-valine methyl ester hydrochloride of formula (V) in the presence of a base in a solvent to produce N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester of formula (VI); (ii) treating the compound VI of step (i) with acid followed by treating with base to produce pure compound VI substantially free from dimeric impurity of formula (Via); (iii) reacting the pure compound of formula (VI) with n-valeryl chloride in the presence of a base to produce pure N-valeryl-N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester (VII) substantially free from alkene impurity of formula (Vila); (iv) reacting the compound of formula (VII) with trialkyltin chloride and a metal azide in a solvent at a reflux temperature to produce N-(1-oxopentyl)-N-[[2′-(2-tributyltintetrazol-5-yl)-(1,1′-biphenyl)-4-yl]methyl]-(L)-valine methyl ester of formula (VHIb) free from thermal degradation impurity (Villa); (v) hydrolyzing the compound of formula (VHIb) in the presence of alkaline conditions to produce Valsartan (I).