Patent ID: 8362269
Filing Date: 2013-01-29
Classification: C07D

Abstract:
1. A process for preparing 1,7′-dimethyl-2′-propyl-2,5′-bi-1H-benzimidazole of formula (I) the process comprising reacting N-methyl-o-phenylene-diamine of formula (II) or a salt thereof with 2-propyl-4-methyl-1H-benzimidazole-6-carboxylic acid of formula (III) or a salt thereof wherein: (a) the compound of formula (III) or one of the salts thereof is dissolved in a polar solvent, (b) the compound of formula (II) or one of the salts thereof is added to this solution, (c) then phosphorus pentoxide is added to this mixture of the two starting compounds in a polar solvent, and (d) the reaction is carried out in a temperature range of up to 160° C.