Patent ID: 8987469
Filing Date: 2015-03-24
Classification: C07D

Abstract:
1. A method for the preparation of 4-(1-methyl-5-nitro-1H-benzimidazol-2-yl)butanoic acid (4), from 2-fluoro-5-nitroaniline, comprising the steps: a) conversion of 2-fluoro-5-nitroaniline to 5-(2-fluoro-5-nitroanilino)-5-oxopentanoic acid (1) using glutaric anhydride: b) conversion of the reaction product (1) of step a) to methyl ammonium 5-[2-(methylamino)-5-nitroanilino]-5-oxopentanoic (2) using methylamine: c) conversion of the reaction product (2) of step b) to 5-[2-(methylamino)-5-nitroanilino]-5-oxopentanoic acid (3):  and d) condensation of the reaction product (3) of step c) to 4-(1-methyl-5-nitro-1H-benzimidazol-2-yl)butanoic acid (4):