One-pot syntheses of 5-oxo-1,4,5,6,7,8-hexahydroquinolines and pyrimido[4,5-b]quinolines using microwave irradiation and ultrasound

A rapid and efficient method for the synthesis of alkyl 4-aryl-1,4,5,6,7,8-hexahydro-2,7,7-trimethyl-5-oxoquinoline-3-carboxylates by the condensation of 5,5-dimethylcyclohexane-1,3-dione and aromatic aldehydes with methyl 3-aminocrotonate or ethyl acetoacetate in the presence of ammonium acetate and of pyrimido[4,5-b]quinolines by the condensation of N-methylaniline with an aromatic aldehyde and 1,3-diaryl-2-thiobarbituric acid using microwave- and ultrasound-induced methods is reported.