A simple and eco-friendly synthesis of the biologically important spirooxindole scaffold was done by the reaction of isatin with activated pyrazolones in the presence of a catalytic amount of p-toluenesulfonic acid in water at room temperature. A variety of symmetrical spirooxindole derivatives were obtained with excellent yields within short reaction time. This method is of great value because of its environmentally benign character, high yield, and easy handling.
Ag NPs decked GO composite as a competent and reusable catalyst for ‘ON WATER’ chemoselective synthesis of pyrano[2,3-c:6,5-c′]dipyrazol]-2-ones
作者:Anshu Dandia、Shyam L. Gupta、Aayushi Indora、Pratibha Saini、Vijay Parewa、Kuldeep S. Rathore
DOI:10.1016/j.tetlet.2017.02.014
日期:2017.3
We have synthesized and characterized Ag NPs decked GO composite and studied its role as reusable catalyst for the 'ON WATER' chemoselective synthesis of pyranodipyrazolones via the reaction of different carbonyl compounds with 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one. This method illustrates significant selectivity for pyranodipyrazolones over arylmethylene bispyrazolols and arylmethylenepyrazolones. Synergistic effect of heterogenic nature of water with reactants and Ag NP5/G0 had profuse outcome on reaction as indicated by high TOF (18.03 x 10(-5) mol g(-1) min(-1)). Furthermore, catalyst was recycled for 7-times without significant loss of activity. (C) 2017 Elsevier Ltd. All rights reserved.