Trifluoroacetic acid → N-Isopropyl-4-fluoro-2-nitroaniline

Participants

Reaction Steps

4-fluoro-2-nitroaniline (15.6 g; 0.1 mole), 2,2-dimethoxypropane (24.6 ml; 0.2 mole) and trifluoroacetic acid [TFA] (23.1 ml; 0.005 moles) were dissolved in toluene (500 ml) and stirred for 1 hr. BH3 * pyridine (10.0 ml; 0.1 moles) was added in 1.0 ml increments. The reaction was exothermic, and the reaction progress was monitored by tlc 40% EtOAc/Hexane. Additional TFA, BH3 * pyridine and 2,2-dimethoxypropane were added until the tlc indicated that the 4-fluoro-2-nitroaniline was consumed. The reaction mixture was placed on a bed of silica and eluted with 10% methyl-t-butylether/hexane. The product was the first major component to elute, which produced 11.2 g (58%) of a yellow oil.

Provenance & Evidence