An expeditious and efficient synthesis of spiro-pyrazolo[3,4-b]pyridines catalysed by recyclable mesoporous aluminosilicate nanoparticles in aqueous-ethanol

A rapid and convenient, environmentally benign protocol for the synthesis of new spiro-pyrazolo[3,-4b]pyridine derivatives in satisfactory yields was developed by the three-component coupling of isatin, cyclic-1,3-dione and pyrazol-5-amine in aqueous ethanol using aluminosilicate nanoparticles as catalyst. We have synthesized heterogeneous aluminosilicate nanoparticles by a room temperature procedure that acts as a very efficient catalyst for this synthesis. The spiro-pyrazolo-pyridines hereby synthesized, may lead to possible pharmacological applications. (C) 2015 Elsevier Ltd. All rights reserved.