Reaction of 2-nitrothiophen with secondary aliphatic amines

Abstract

Secondary aliphatic amines react with 2-nitrothiophen in ethanol at room temperature to yield bis-(4-dialkylamino-1-nitrobuta-1,3-dienyl) disulphides. The disulphide is shown to be generated via the preliminary formation of the corresponding thiol. A mechanism involving nucleophilic attack by the amine at the 5 position of the nitroactivated thiophen ring, and proton tranfer to yield a sulphonium-type intermediate followed by ring-opening, is proposed.