A facile synthesis of furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5(7H)‐one derivatives via three‐component reaction in ionic liquid without any catalyst

Abstract

Abstract magnified imageA series of furo[3,4‐e]pyrazolo[3,4‐b]pyridine‐5(7H)‐one and indeno[2,1‐e]pyrazolo[3,4‐b]pyridine‐5(1H)‐one derivatives were synthesized via the three‐component reaction of an aldehyde, 5‐aminopyrazole and either tetronic acid or 1,3‐indanedione in ionic liquid without any catalyst. The structures of the products have been established by spectroscopic data and further confirmed by X‐ray diffraction analysis. This method has the advantages of easier work‐up, mild reaction conditions, high yields and an environmentally benign procedure. J. Heterocyclic Chem., 46, 469 (2009).