Synthesis of 1-Naphthylacetylene Sulfides from 4-(1-Naphthyl)-1,2,3-thiadiazole

Abstract

4-(1-Naphthyl)-1,2,3-thiadiazole is readily decomposed under the action of potassium tert-butylate with the release of nitrogen and the formation of potassium 2-(1-naphthyl)ethynylthiolate. Upon further treatment of the reaction mixture with excess of alkyl halide, the corresponding alkyl 2-(1-naphthyl)-1-ethynylsulfides have been obtained. In the case of the reaction with allyl bromide, the resulting sulfide has undergone rearrangement. A mixture of Z- and E-isomers of 2-(1-naphthyl)-1-ethynyl-1-propenylsulfide has been obtained as the product of allylic rearrangement instead of the expected product of the thio-Claisen rearrangement.