Hydrochloric Acid → 2,6-Difluorobenzoyl isocyanate

Participants

Reaction Steps

In order to synthesize the isocyanate, 1.57 g (10 mmol) of 2,6-difluorobenzamide and 15 ml of dry 1,2-dichloroethane were introduced into a 100 ml flask and then 0.92 g (10.5 mmol) of oxalyl chloride was slowly added thereto at normal temperature by means of a syringe, during which an exothermic reaction occurred that generated hydrochloride gas. The resulting reaction mixture was refluxed for 5 hours and cooled to normal temperature. The reaction solvent and the excess oxalyl chloride were removed therefrom under vacuo to obtain 2,6-difluorobenzoyl isocyanate in an oily state. Thus obtained 2,6-difluorobenzoyl isocyanate was then dissolved in 20 ml of dry 1,2-dichloroethane. Then, 2.63 g of 2-chloro-3,5-bis(trifluoromethyl)aniline was added thereto, reacted for 3 hours, and filtered to obtain 4.15 g (Yield from benzamide, 93%) of the title compound as a solid.

Provenance & Evidence