Synthesis of 4-[5-(Phenylsulfonylmethyl)thien-2-yl]-1,2,3-thiadiazoles

A series of 5-(phenylsulfonylmethyl)-2-acetylthiophenes was synthesized by the reaction of 5-bromomethyl-2-acetylthiophene with 4-substituted potassium phenylsulfinates. They were converted to carboethoxyhydrazones by treating with carboethoxyhydrazine in benzene under reflux in the presence of p-toluenesulfonic acid. 4-[5-(Phenylsulfonylmethyl)thiophen-2-yl]-1,2,3-thiadiazoles were prepared when treating carboethoxyhydrazones with thionyl chloride. 4-Bromosubstituted analogs were synthesized by the reaction of 4-(4-bromo-5-bromomethylthiophen-2-yl)-1,2,3-thiadiazole with potassium phenylsulfinates.