A SIMPLE, EFFICIENT AND SOLVENT F REE ONE POT SYNTHESIS OF 3, 3 DIHETER OAROMATIC OXINDOLE

Formic acid catalyzed, single step and environmentally friendly process for synthesis of 3, 3 - diheteroaromatic oxindole derivatives is described. This adopted protocol for Friedel - Crafts substitution reaction has the advantage of reusability of the catalyst, high yields and ease of separation of pure products.