Annulation of 2'-Chlorochalcones and Elemental Sulfur toward the Synthesis of 2-Aryl Thiochromenones

Herein we report a method for the synthesis of 2-aryl thiochromenones via a sulfuration of 2'-chlorochalcones. The chalcones could be prepared in advance or in situ obtained from 2'-chloroacetophenones and aromatic aldehydes. The conditions were tolerant of functionalities including chloro, fluoro, methylthio, phenoxy, and trifluoromethyl groups. 2-Heteroaryl thiochromenones could also be obtained in moderate yields. Our method appears to be a simple, general tactic to afford 2-aryl thiochromenones from commercial starting materials.