An efficient catalyst-free approach for the synthesis of novel isoxazolo[5,4- b ]pyridine derivatives via one-pot three-component reaction

A catalyst-free, one-pot, three-component condensation procedure for the synthesis of novel isoxazolo[5,4- b ]pyridine derivatives has been reported by condensation of isatins, 3-methylisoxazol-5-amine, and cyclic enolizable carbonyl compounds in ethylene glycol at 80 °C. The structures of the synthesized compounds have been confirmed by spectral and X-ray studies. Crystal packing of one compound has also been reported. Less reaction time, easy work-up, and high yields are the important features of the present protocol. Graphical abstract