Ultrasound-accelerated synthesis of 1,4-dihydropyridines in an ionic liquid

Hantzsch 1,4- dihydropyridine compounds were synthesized efficiently in high yields at room temperature within short times in 1,1,3,3- N, N, N', N'-tetramethylguanidinium trifluoroacetate as ionic liquid using ultrasound irradiation. The ionic liquid can be recovered conveniently and reused efficiently.