Rapid Microwave‐Assisted Liquid‐Phase Synthesis of 4‐Substituted‐5‐methoxycarbonyl‐6‐methyl‐3,4‐dihydropyridones on Poly(ethylene Glycol) Support

Abstract

4‐Substituted‐5‐methoxycarbonyl‐6‐methyl‐3,4‐dihydropyridones have been efficiently prepared on the soluble polymer polyethylene glycol (PEG) 4000 by solvent‐free microwave irradiation through a one‐pot condensation of PEG‐bound acetoacetate, Meldrum's acid, ammonium acetate, and the appropriate aldehyde in the presence of a catalytic amount of polyphosphoric acid. The polymer‐supported synthesis provided the target compounds in excellent yield and purity with a facile workup procedure.

Keywords:

• Liquid‐phase synthesis
• microwave irradiation
• PEG‐bound acetoacetate
• 4‐substituted‐5‐methoxycarbonyl‐6‐methyl‐3,4‐dihydropyridones

Acknowledgment

We gratefully acknowledge financial support from the National Natural Science Foundation (NSF) of China (No. 20562005) and NSF of Jiangxi Province (No. 0620021 and No. 2007GZW0185).