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:
Jun. 07, 2005
Filed:
Jul. 02, 2003
Ramesh Dandala, Hyderabad, IN;
Umashankar Das, Saskatoon, CA;
Divvela Venkata Naga Srinivasa Rao, Hyderabad, IN;
Meenakshisunderam Sivakumaran, Hyderabad, IN;
Ramesh Dandala, Hyderabad, IN;
Umashankar Das, Saskatoon, CA;
Divvela Venkata Naga Srinivasa Rao, Hyderabad, IN;
Meenakshisunderam Sivakumaran, Hyderabad, IN;
Aurobindo Pharma Ltd., Hyderabad, IN;
Abstract
This invention relates to a novel process to obtain highly pure 4-(cyclopropylcarbonyl)-α,α-dimethylphenylacetic acid of Formula I through crystallization from a mixture of para and meta regioisomers of Formula I and II in cyclohexane, whereby the amount of undesired meta isomer, 3-(cyclopropylcarbonyl)-α,α-dimethylphenylacetic acid of Formula IIis decreased to below 0.5%. The compound of Formula I is a key intermediate for the preparation of high purity terfenadine carboxylate, which is a known antihistaminic.