Ultrasound-assisted one-pot, four component synthesis of 4-aryl 3,4-dihydropyridone derivatives

The condensation of Meldrum’s acid, aromatic aldehydes, alkyl acetoacetates and ammonium acetate in glacial acetic acid under ultrasound irradiation at room temperature results in the formation of 3,4-dihydropyridone derivatives (4a–p) in 85–96% yields. Compared with conventional methods, the main advantages of the present procedure are milder conditions, shorter reaction times and higher yields.