Diazaindenes (azaindoles). Part II. Thermal indolisation of 3- and 4-pyridylhydrazones

Abstract

Thermal indolisation of 4-pyridylhydrazones has yielded a series of 1,5-diazaindenes (pyrrolo[3,2-c]pyridines), and 3-pyridylhydrazones similarly gave mixtures of a 1,4-diazaindene (pyrrolo[3,2-b]pyridine)(major isomer) and a 1,6-diazaindene (pyrrolo[2,3-c]pyridine). Correlations of structure with t.l.c. behaviour and with u.v. and i.r. spectra are discussed.