Hydrochloric Acid → 1-Chloro-5-fluoro-4-isocyanato-2-nitrobenzene

Participants

Reaction Conditions

Reaction Steps

Dry HCl gas is passed into a solution of 66.7 g (0.35 mol) of 4-chloro-2-fluoro-5-nitroaniline in 1180 ml of toluene at 0° to 5° C. until the solution is saturated. 34.7 g (0.35 ml) of phosgene are subsequently metered in, and the mixture is heated slowly at 85° C. After a further 17.3 g (0.175 mol) of phosgene have been added and the mixture has been heated at 85° C. (1 h), the batch is flushed with nitrogen until free from phosgene and cooled. Removal of the precipitate by filtration and concentration gives 28.6 g (37.7% of theory) of 4-chloro-2-fluoro-5-nitrophenyl isocyanate of melting point 43°-46° C.; boiling point 125° C. at 0.3 torr (bulb-tube distillation).

Provenance & Evidence