Reactant for synthesis of oxazino[4,3-a]indoles via cascade addition-cyclization reactions, reactant for preparation of indolecarboxamides as cannabinoid CB1 receptor antagonists, reactant for preparation of indole-3-propionic acids as antiinflammatory and analgesic agents, reactant for Friedel-Crafts acylation with nitrobenzoyl chloride. Indole ring system is an important building block or intermediate in the synthesis of many pharmaceutical agents. It is formed during the Fischer indolization of ethyl pyruvate 2-[2-(methanesulfonyloxy)-4-methyl]phenylhydrazine. ? Reactant for oximation reactions