The synthesis of substituted indazoles via cyclization of various hydrazones in the presence of polyphosphoric acid (PPA)

Research directed toward the discovery of nitric oxide synthase inhibitor led to synthesis of a series of substituted indazoles via the intramolecular cyclization of various hydrazones of substituted acetophenones and benzophenones in the presence of polyphosphoric acid (PPA). The structures of the indazoles were determined by elemental analysis, H nmr, ir, and ms.