Iminocyclopropa[l]phenanthrenes by the condensation of diarylaminoguanidines with 9,10-phenanthraquinone–a reinvestigation

Abstract

Heating of the phenanthraquinone 4-aryl-3-(arylimino)semicarbazones (3a) and (3b) led to the phenanthraquinone 4-arylsemicarbazones (6a) and (6b). A statement in the literature that this reaction gives rise to 1-arylimino-1H-cyclopropa[l]phenanthrenes could not be confirmed. The constitution of (6a) was confirmed by independent synthesis from 4- phenylsemicarbazide and phenanthraquinone.