Patent ID: 8394961
Filing Date: 2013-03-12
Classification: C07D

Abstract:
1. A method for the production of dabigatran of formula VIII by reaction of 4-ethylamino-3-nitrobenzoic acid chloride with ethyl-3-(pyridin-2-ylamino)propanoate, reduction of the nitro group, subsequent reaction with [(4-cyanophenyl)amino]acetic acid, hydrolysis and reaction with ammonium carbonate and conversion to dabigatran by reaction with hexyl chloroformate, wherein the product of the reaction of 4-ethylamino-3-nitrobenzoic acid chloride with ethyl-3-(pyridin-2-ylamino)propanoate is converted to the hydrochloride using a hydrogen chloride solution to produce the compound of formula III-HCl the nitro group of which is reduced by reaction with sodium dithionite and the resulting compound of formula IV is subjected to reaction with [(4-cyanophenyl)amino]acetic acid of formula V and oxalic acid, the product of this reaction of formula VI-oxal is then subjected to hydrolysis and reaction with ammonium carbonate to produce the intermediate of formula VII-HCl, which is then converted to dabigatran by reaction with hexyl chloroformate.