Oxalyl chloride → 2,6-Difluorobenzoyl isocyanate

Participants

Reaction Steps

A solution of 1.7 g. of 2,6-difluorobenzamide in 50 cc of dichloroethane was heated to 50° C. and 4.2 g. of oxalyl chloride was added dropwise with stirring and the reaction was continued for 1 hour with stirring to obtain 2,6-difluorobenzoyl isocyanate. Then, dichloroethane and excess of oxalyl chloride were distilled off under a reduced pressure. The residue was admixed with 50 cc of dioxane and a solution of 3.3 g. of 3-ethoxycarbonyl-4-(3-chloro-5-trifluoromethyl-2-pyridyloxy) aniline in dioxane was added dropwise and the reaction was continued for 2 hours with stirring. After the reaction, the reaction mixture was poured into water and the resulting crystal was filtered and washed with water and dried to obtain 4.8 g. of the object compound having a melting point of 183°-186° C.

Provenance & Evidence