SILICA SUPPORTED POLYPHOSPHORIC ACID CATALYZED SYNTHESIS OF SUBSTITUTED INDAZOLES

Santosh Vikram Raut, Bharat K. Dhotre, Shivshanklar P. More, Atul D. Tidke, Mohd Arif Ali Khan Pathan
2019 European Chemical Bulletin  
A clean and straightforward methodology developed for the synthesis of substituted indazoles using silica supported polyphosphoric acid (PPA-SiO2) catalyzed condensation reaction between substituted 2-hydroxybenzaldehydes or acetophenones and hydrazine hydrate or phenylhydrazine. The reaction conditions are optimized for different solvents at different temperatures. The yield of the products improved to 88 to 90 % using silica supported polyphosphoric acid as a catalyst, which is reusable,
more » ... h is reusable, cost-effective and straightforward to synthesize.
doi:10.17628/ecb.2019.8.137-140 fatcat:mdin3zukjbhsraeostmxa2we7u