Butadiene sulphone chemistry. Part I. Addition reactions

Abstract

Butadiene sulphone [2,5-dihydrothiophen dioxide (I)] and 2,3-dihydrothiophen dioxide (II) undergo addition reactions with hydrazine and with substituted hydrazines; either the NN- or the NN′-disubstituted hydrazine is formed, depending on the nature of the original substituent and on the reaction conditions. The NN′-compounds are readily oxidised to azo-compounds. The dihydrothiophen dioxides and substituted analogues also undergo the Michael reaction with donors such as malonic or cyanoacetic ester, benzyl cyanide, nitroparaffins, and acetophenone, and under special conditions with acetoacetic ester. Some further reactions of the adducts are described, including Nef reactions of the nitroalkyl derivatives (XV) which give acyltetrahydrothiophen dioxides. Addition of hydrogen cyanide occurs less readily than does the Michael addition. Hydriodic acid, but not hydrobromic acid, adds to 2,3-dihydrothiophen dioxide, and action of halogens in moderately concentrated nitric acid affords nitrate esters of halogenohydrins from which the halogenohydrins are readily formed by mild hydrolysis. Ammonium hydrogen sulphite readily adds to 2,3-dihydrothiophen dioxides to give the 3-sulphonic acid salts, which undergo the usual reactions.