Abstract 5-Substituted tetrazoles readily react with trifluoroacetic anhydride at 20–25° C to give the corresponding 2-substituted 5-trifluoromethyl-1, 3, 4-oxadiazoles, in contrast to published data according to which the title compounds are converted into 1, 3, 4-oxadiazole derivatives on heating with carboxylic acid anhydrides or chlorides at 100–120° C. The reaction is governed not only by the rate of acylation of the tetrazole ring and temperature ...
