Deacylation during the synthesis of new 4-amino-1H-pyrazolo [3,4-b] pyridines catalysed by SnCl4

Abstract

A series of novel 1-(4-amino-6-methyl-1-aryl-1H-pyrazolo[3,4-b]pyridin-5-yl)- ethanones and 6-methyl-1-aryl-1H-pyrazolo[3,4-b]pyridin-4-amines were prepared by the annulation of 5-amino-1-aryl-1H-pyrazole-4-carbonitriles with acetylacetone in the presence of tin(IV) chloride. The results demonstrated that the ethanones are the precursors of second compounds.