Application of β-(2-Chloroaroyl)thioacetanilide in Synthesis(III): An Efficient Three-Component Synthesis of Thiochromeno[2,3-b]pyridines Catalyzed by KF/Neutral A12O3 Co-operated with PEG 6000 under Microwave Irradiation

摘要

A series of new functionalized thiochromeno[2,3-b]pyridine derivatives have been synthesized via a sequence of Knoevenagel condensation, Michael addition, cyclization, and intramolecular nucleophilic substitution, which is first catalyzed by KFeutral A12O3 cooperated with PEG 6000 under microwave irradiation. Experimental results indicated that among the catalysts tested, KF/ neutral A12O3 with PEG 6000 exhibits the best catalytic activity, which leads to a substantial improvement in the overall yield and purity of the desired final products and significantly shorter reaction time.