Patent ID: 8658821
Filing Date: 2014-02-25
Classification: A61P,C07C

Abstract:
1. A one-pot for the preparation of nateglinide, which process comprises (1) reacting a mixture consisting essentially of a dehydrating agent, a base, an alkyl ester of D-phenylalanine of formula (II): where R represents C where X represents hydroxy or halo, to obtain a C (2) followed by hydrolysis to yield nateglinide of formula (I): wherein the step (1) comprises initially reacting D-phenyl alanine with a solution of thionyl chloride in a C 1-4 alcohol to give the corresponding alkyl ester of formula (II) as the hydrochloride salt, which is converted in situ to the free base which is then reacted with trans-4-isopropylcyclohexanecarboxylic acid or trans-4-isopropylcyclohexanecarboxylic acid halide of above formula (III) in the presence of a dehydrating agent and wherein said in situ conversion is carried out using a base comprising aqueous ammonia.