A Useful Crystalline Trifluoroacetylating Reagent

(Trifluoroacetyl)benzotriazole (1) is a crystalline trifluoroacetylating reagent and used for the direct trifluoroacetylation of amines and alcohols without any base. The trifluoroacetylation with amines is carried out at room temperature in good yields when primary and secondary amines and low nucleophilic aniline derivatives are employed as reactants. On the other hand, the trifluoroacetylation with alcohols proceeds with refluxing THF. All primary and secondary alcohols and phenols including such a high-acidic phenol as 4-nitrophenol are available for this trifluoroacetylation. 1 has advantages of a crystalline solid and is easy to weigh, and can be used for the direct introduction of a trifluoroacetyl group under mild conditions. Thus, 1 is a useful trifluoroacetylating reagent.