Green catalyst-free one-pot synthesis of novel tetrahydropyridine-3-carboxamides by microwave-assisted approach

A clean, facile and catalyst-free four-component domino reaction of aromatic aldehyde, ethyl cyanoacetate, acetoacetanilide and ammonium acetate in ethanol under microwave irradiation (MWI) conditions is described. Eleven novel and diverse tetrahydropyridine-3-carboxamide derivatives were synthesized in excellent yields (91-97%) using this green protocol. The significant benefits of this method are simple handling, ethanol as solvent, catalyst-free reaction under mild conditions, short reaction times (<10 min) and excellent product yields. Easy workup procedure and simple purification technique of the target molecules evade column chromatography. Graphic Novel tetrahydropyridine-3-carboxamide derivatives were synthesized under the microwave irradiation (MWI) method in short reaction time (<10 min). All the synthesized compounds confirmed by various spectroscopic techniques such as H-1 NMR, C-13 NMR, N-15 NMR and HRMS. Ethanol as a solvent, easy workup procedure and simple handling are the benefit of green protocol.