An efficient and odourless synthesis of thia-Michael adducts by the reaction of various organic halides (primary, secondary, tertiary, allylic, and benzylic), Structurally diverse electron-deficient alkenes (ketones, esters, and acrylonitrile) and thiourea in the presence of sodium carbonate in wet polyethylene glycol (PEG 200) at 30-35 degrees C has been developed. This protocol is also a highly useful method for large-scale operation. (C) 2009 Elsevier Ltd. All rights reserved.