Synthesis of 4-Sulfanylcoumarins Using Thiourea and Alkyl Halides as the Sulfanylation Agent in Polyethylene Glycol-Water
摘要:
A novel and efficient route for the synthesis of 4-sulfanylcoumarins is disclosed. The direct sulfanylation of 4-tosyloxycoumarins with thiourea and various alkyl halides in polyethylene glycol 200-water ( PEG 200-H2O), at room temperature under an air atmosphere, affords the corresponding 4-sulfanylcoumarins in moderate to excellent yields. This transformation shows good substrate scope and takes place in a green solvent.