Patent ID: 7294721
Filing Date: 2007-11-13
Classification: C07D

Abstract:
1. A process for preparing (R)-2-(4-amidinophenylaminomethyl)-1-methyl-5-[1-(carboxymethylamino)-1-(pyrrolidinocarbonyl)-ethyl]-benzimidazole-monohydrochloride, comprising the following steps: (a) alkylating the free amino group of the compound (R)-2-(4-cyanophenylaminomethyl)-1-methyl-5-[1-amino-1-(pyrrolidinocarbonyl)-ethyl]-benzimidazole of the formula (II): with a compound of the formula III wherein R denotes a C 1-3 -alkyl group and X denotes a leaving group, thereby obtaining a compound of general formula wherein R denotes a C 1-3 -alkyl group; (b) converting the compound of the formula (IV) obtained in (a) into an amidine of the formula V wherein R denotes a C 1-3 -alkyl group; (c) precipitating an intermediate compound of the formula (V) as the p-toluenesulphonic acid salt of the formula VI wherein R denotes a C 1-3 -alkyl group; (d) converting a compound obtained according to (c) into the base (VII) and subsequently precipitating the free base (R)-2-(4-amidinophenylaminomethyl)-1-methyl-5-[1-(carboxymethylamino)-1-(pyrrolidinocarbonyl)-ethyl]-benzimidazole of formula VII and (e) precipitating the monohydrochloride of the formula (I) by suspending the base obtained in (d) in a solvent or mixture of solvents, optionally heating the reaction mixture to a temperature between 20° C. and the reflux temperature of the solvent or mixture of solvents and adding hydrogen chloride.