Difluoroacetic acid → 4-bromo-2-(difluoromethyl)-6-nitro-1H-benzo[d]imidazole

Participants

Reaction Conditions

Reaction Steps

To a 100 mL round bottomed flask was added 3-bromo-5-nitrobenzene-1,2-diamine (5.5 g, 23.70 mmol) and 2,2-difluoroacetic acid (4.46 mL, 71.1 mmol) in Toluene (55 mL). The stirred solution was heated to 105° C. and monitored by LC/MS. After stirring at 105° C. for 2 hr the reaction was allowed to cool to rt, was diluted with EtOAc (20 mL) and filtered through celite. The filtrate was concentrated in-vacuo then taken up in EtOAc, washed several times with sat'd NaHCO3 soln, brine and then dried over Na2SO4 and concentrated to provide crude 4-bromo-2-(difluoromethyl)-6-nitro-1H-benzo[d]imidazole (6.7 g, 22.94 mmol, 97% yield) as a brown solid. LC/MS: MS (ES+) m/e 293.7 [M+H]+.

Provenance & Evidence