An efficient synthesis of coumarin- and quinolone-annulated thiazole derivatives via ligand-free iron (III)-catalyzed coupling followed by acid-promoted condensation

An efficient strategy for the synthesis of coumarin- and quinolone-annulated thiazole derivatives using sodium sulfide as a sulfur source has been achieved via ligand-free iron (III)-catalyzed coupling followed by acid-promoted condensation. This synthetic protocol is one-pot, less expensive, and affords the products in good yields.