An Efficient One-pot Three-component Method for the Synthesis of 5-Amino-3-(2-oxo-2H-chromen-3-yl)-7-aryl-7H-thiazolo[3,2-a]pyridine-6,8-dicarbonitriles

摘要

A facile, convenient, and adequate method has been developed for the synthesis of novel 5-amino-3-(2-oxo-2H-chromen-3-yl)-7-aryl-7H-thiazolo[3,2-a]pyridine-6,8-dicarbonitriles (6) by employing 2-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)acetonitrile (3) as an important precursor. Initially, we have synthesized the target compounds in a stepwise manner and then approached a tandem method to examine the feasibility of one-pot method. Subsequently, one-pot three-component protocol has been established for the synthesis of title compounds by the reaction of 3 with benzaldehyde and malononitrile in refluxing ethanol engender a new six-membered thiazolo[3,2-a] pyridine as a hybrid scaffold. Reaction conditions were optimized for this reaction and a broad substrate scope with various aryl and heteroaryl aldehydes make this protocol very practical, attractive, and worthy. Mechanistic aspects for the formation of these compounds were outlined comprehensively. Characterization of these newly synthesized compounds was achieved by means of IR, H-1 NMR, C-13 NMR, and HRMS.