Application of ortho-chloro-β-aroylthioamides in synthesis(II): an efficient one-pot, three-component synthesis of tricyclic thiochromeno[2,3-b]pyridine derivatives

Tricyclic thiochromeno[2,3-b]pyridine derivatives have been successfully synthesized in an unusual one-pot multicomponent cascade reaction from ortho-halo-β-aroylthioamides, Meldrumʹs acid, and aromatic aldehydes. The reaction presumably proceeds via Knoevenagel condensation–Michael addition–cyclocondensation–decarboxylation–rearrangement–intramolecular SNAr reaction sequence. High bond forming efficiency of this reaction makes it attractive for the synthesis of thiochromeno[2,3-b]pyridine derivatives in a single step operation.