Acetic Anhydride → 5-Acetamido-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole

Participants

Reaction Steps

5-Amino-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (28.7 g) was heated at reflux in acetic anhydride (150 ml) for 8 hours. The reaction mixture was then evaporated to dryness and the solid residue was suspended in ethanol (250 ml). Saturated aqueous sodium bicarbonate solution was then added to give a pH of 8 and the suspension was then stirred magnetically for 16 hours. The solid obtained was separated by filtration, washed with water and dried, to give 5-acetamido-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (23.7 g), m.p. 222°-224° C., in the form of an off-white powder.

Provenance & Evidence