Hydrochloric Acid → 2-O-acetyl-2'-trifluoromethyl-4',5-dicyano-3-t-butyl-6-methylsalicylanilide

Participants

Reaction Steps

A solution of acetic anhydride (0.1 ml.) in dry pyridine (1 ml.) is added dropwise to a stirred solution of 2'-trifluoromethyl-4',5-dicyano-3-t-butyl-6-methylsalicylanilide (0.38 g.) in dry pyridine (4 ml.) at 0°-5° C. The mixture is stirred at 0°-5° C. for 1 hour and then at room temperature until no starting salicylanilide is left, as shown by the absence of the characteristic ferric chloride positive spot, on TLC analysis on silica using chloroform as eluant. The mixture is then poured onto a mixture of ice (30 g.) and 2N hydrochloric acid solution (20 ml.). The solid which is formed is collected and washed with water. After drying, the solid is recrystallised from a mixture containing equal parts of ether and cyclohexane to give 2-O-acetyl-2'-trifluoromethyl-4',5-dicyano-3-t-butyl-6-methylsalicylanilide, m.p. 171°-172° C., having spectroscopic properties consistent with those of an O-acetate.

Provenance & Evidence