Regioselective Synthesis of 3‐Benzoyl‐4‐Phenyl‐4 <i>H</i> ,5 <i>H</i> ‐Thiopyrano[2,3‐ <i>b</i> ]chromen‐5‐One Derivatives through One‐Pot Domino Reaction Using Aromatic Aldehyde, β‐Enaminone, and 4‐Hydroxy‐2 <i>H</i> ‐Chromene‐2‐Thione

A green, efficient, and regioselective one‐pot three‐component synthesis of 3‐benzoyl‐4‐phenyl‐4 H ,5 H ‐thiopyrano [2,3‐ b ]chromen‐5‐one derivatives has been developed. This protocol utilizes 4‐hydroxy‐2 H ‐chromene‐2‐thione, aromatic aldehydes, and β ‐enaminones, mediated by triphenylphosphine and N‐ bromosuccinimide. Notably, this protocol involves a Michael‐type addition followed by intramolecular cyclization. This methodology offers excellent product yields under mild reaction conditions, making it a valuable addition to synthetic protocols.