Divinyl Sulfide as Synthetic Equivalent of Ethenethiolate and 3-Butenethiolate Anions in Nucleophilic Substitution in Halopyridines and Haloalkanes

Abstract

The use of divinyl sulfide as synthetic equivalent of ethenethiolate and 3-butenethiolate anions makes it possible to obtain vinylthio(halo)- and 3-butenylthio(halo)pyridines from halopyridines. 2,6-Bromo(chloro)pyridines react with a mixture of ethenethiolate and 3-butenethiolate ions more readily than does 3,5-dibromopyridine. The reaction yields mainly products of halogen replacement by vinylthio group. The formation of 3-butenethiolate ion in the reaction of divinyl sulfide with sodium in liquid ammonia is governed by the order of mixing of the reactants. Possible ways of generation of 3-butenethiolate ion in the reaction with 1-bromobutane are discussed.