申请人:Heyl Chemisch-pharmazeutische Fabrik GmbH & Co. KG
公开号:US20140031560A1
公开(公告)日:2014-01-30
The present invention relates to a method for preparation of alkyl 4-[5-[bis(2-hydroxyethyl)amino]-1-methyl-1H-benzimidazol-2-yl]butanoate (7) from 2-fluoro-5-nitroaniline, comprising the steps of: (a) conversion of 2-fluoro-5-nitroaniline to 5-(2-fluoro-5-nitroanilino)-5-oxopentanoic acid (1) using glutaric anhydride, conversion of compound (1) to methylammonium 5-[2-(methylamino)-5-nitroanilino]-5-oxopentanoate (2) using methylamine; conversion of compound (2) to 5-[2-(methylamino)-5-nitroanilino]-5-oxopentanoic acid (3) and condensation of compound (3) to 4-(1-methyl-5-nitro-1H-benzimidazol-2-yl)butanoic acid (4); (b) esterification of the product (4) of step a) to alkyl 4-(1-methyl-5-nitro1H-benzimidazol-2-yl)butanoate (5); (c) reduction of the product of step b) to alkyl 4-(5-amino-1-methyl-1H-benzimidazol-2-yl)butanoate (6), and (d) conversion of the product of step c) to alkyl 4-[5-[bis(2-hydroxyethyl)amino]-1-methyl-1H-benzimidazol-2-yl]butanoate (7)