An unknown route of cyclocondensation of peri-acetylenylquinones with hydrazine

Cyclocondensation of 3-diethylamino-5-phenylethynyl-l,4-naphthoquinone with NH2NH2 resulting in the closure of a pyridazine ring is reported. This hydrazine condensation was unknown for peri-acetylenic derivatives of polycyclic quinones.