Abstract

Isothiocyanatosulfonamides in heterocyclic synthesis: Synthesis and biological activity of some thiophene derivatives containing sulfonamidomoiety

Author(s): Abu-Bakr A.M.El-Adasy

Reaction of isothiocyanatosulfonamides (2a,b) with ethyl benzoylacetate in basicN,N-dimethylformamide gave the non-isolated potassiumsalts (3a,b) which were treated with HCl to give the corresponding thiocarbamoyl derivatives (4a,b). The non-isolated adducts (3a,b) underwent heterocyclization upon treatment with halo compounds to give the corresponding thiophene derivatives (6a,b, 11, 14, 16 and 18). Compound (3b) treatment with chloroacetyl chloride to give the corresponding thiazolidinone derivative (20).Also, compound (3b) reactedwith dimethyl sulfate to give keteneN, Sacetal derivative (21). Finally, treatment of keteneN,-S-acetal 21with hydrazine hydrate yielded the corresponding pyrazolone derivative (22). Structures of the newly synthesized compounds were elucidated on the basis of elemental analysis and spectral data.