Unsymmetrical polynuclear cinnoline derivatives. Part II. Some pentacyclic and methyl substituted tetracyclic cinnolines

Abstract

Cyclisation with sulphuric acid of a number of cyclohexane-1,2-dione 1-arylhydrazones and 4-methylcyclohexane-1,2-dione 1-arylhydrazones has produced the corresponding Partially HYDROGENATED Polynuclear cinnolines, a number of which have been dehydrogenated to the fully aromatic cinnolines. Those cyclopentane-1,2-dione 1-arylhydrazones that were investigated failed to cyclise into the expected cinnolines. The tautomerism of the arylhydrazones has been studied by means of their infrared spectra. The action of oxidising and other reagents on the new cinnolines has been studied.