Formic Acid → Methyl 7-fluoro-6-(phenylamino)-1H-benzo[d]imidazole-5-carboxylate

Participants

Reaction Steps

4-Amino-3-fluoro-5-nitro-2-phenylamino-benzoic acid methyl ester 26a (16.70 g, 54.71 mmol), formic acid (250 mL, 6.63 mol) and 20% Pd(OH)2/C (9.00 g, 16.91 mmol) in ethanol (250 mL) are stirred at 40° C. for two hours under N2 and then at 95° C. for 16 hours. The reaction mixture is cooled to room temperature and filtered through Celite rinsing with ethyl acetate. The filtrate is concentrated under reduced pressure to give a yellow solid. The solid is triturated with diethyl ether to give 13.47 g (86%) of the desired product as a tan solid. MS APCI (+) m/z 286 (M+1) detected; MS APCI (−) m/z 284 (M−1) detected.

Provenance & Evidence