Zinc oxide as a new, highly efficient, green, and reusable catalyst for microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters in ionic liquids

Abstract

A simple, clean, and efficient procedure for the green synthesis of some N-alkyl derivatives of sulfonamides is described. Microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters, in the presence of catalytic amount of zinc oxide (ZnO) in 1-butyl-3-methylimidazolium bromide ([bmim]Br), affords the title compounds in high yields and short reaction times.Key words: zinc oxide, green chemistry, microwave, Michael addition, sulfonamide, ionic liquid.