Efficient Synthesis of 6-Amino-8-aryl-2-methyl-1,2,3,4-tetrahydroisoquinoline-5,7-dicarbonitrile Under Solvent-Free Conditions

A series of 6-amino-8-aryl-2-methyl-1,2,3,4-tetrahydroisoquinoline-5,7-dicarbonitriles were prepared in good yields under solvent-free conditions by multicomponent reactions of aromatic aldehyde, malononitrile, and 1-methylpiperidin-4-one in the presence of sodium hydroxide (NaOH). The structures of the products were characterized by infrared, 1H NMR spectra, elemental analysis, and high-resolution mass spectrometery (HRMS).