Patent ID: 8183377
Filing Date: 2012-05-22
Classification: A61P,C07D

Abstract:
1. A process for preparing (6-methyl-2-p-tolyl-imidazo[1,2-a]-pyridin-3-yl)acetic acid (zolpidic acid) of formula (I) which comprises: a) reacting 6-methyl-2-(4-methylphenyl)imidazo[1,2-a]pyridine of formula (II) with oxalyl chloride to form (6-methyl-2-p-tolyl-2,3-dihydro-imidazo[1,2-a]pyridin-3-yl)oxoacetyl chloride of formula (III); b) converting the compound of formula (III) to (6-methyl-2-p-tolyl-2,3-dihydro-imidazo[1,2-a]pyridin-3-yl)-oxoacetic acid of formula (IV) or its salt; and c) reacting the acid of formula (IV) or its salt with hydrazine in presence of a glycol and base to form 6-methyl-2-p-tolyl-imidazo[1,2-a]pyridin-3-yl)acetic acid (zolpidic acid).