Reaction of phenylnitrenium ion with sulphides. A novel synthetic method for aminophenyl sulphide derivatives

Abstract

The reaction of phenyl azide with sulphides in the presence of both trifluoroacetic acid and trifluoromethanesulphonic acid to produce 2- and 4-aminophenyl sulphides (2) and (3) was investigated in order to obtain information on the following points: the kinetics of decomposition of phenyl azide, the effect of addition of benzene to reaction systems, the replacement of phenyl azide by 1-phenyl-2-methyl-4,6-diphenylpyridinium salt, and the steric and electronic effect of substituents in the sulphides. The products are formed through an azasulphonium ion by reaction of phenylnitrenium ion with sulphide, followed by rearrangement of the alkyl group in the azasulphonium ion. Sulphides with primary alkyl groups larger than propyl result in selective formation of ortho-products (2), the mechanism of which is discussed in detail.