Diisopropylethylamine → 2-{[6-(3-Methanesulfonyl-phenylethynyl)-pyridine-2-carbonyl]-amino}-1H-benzoimidazole-4-carboxylic acid methyl ester

Participants

Reaction Steps

To a solution of 136 mg (0.45 mmol) of 6-(3-methanesulfonyl-phenylethynyl)-pyridine-2-carboxylic acid in DMF (2 mL) was added 210 mg (0.55 mmol) of HBTU (210 mg) and DIEA (0.2 mL). The mixture was stirred for 5 min then 96 mg (0.5 mmol) of 2-amino-1H-benzoimidazole-4-carboxylic acid methyl ester (Intermediate A) was added. The reaction mixture was stirred at 30° C. for 30 min. After usual workup as described in general procedure A, 142 mg (60%) of 2-{[6-(3-Methanesulfonyl-phenylethynyl)-pyridine-2-carbonyl]-amino}-1H-benzoimidazole-4-carboxylic acid methyl ester was obtained after column chromatography eluting with DCM/EtOAc (v/v=1:1) then EtOAc. LCMS: 475 (M+1)+. This ester was hydrolyzed as described in general procedure B to provide 135 mg (100%) of 2-{[6-(3-methanesulfonyl-phenylethynyl)-pyridine-2-carbonyl]-amino}-1H-benzoimidazole-4-carboxylic acid. LCMS: 461 (M+1)+.

Provenance & Evidence