The photochemical addition reaction of aldehydes to heterocyclic nitrogen o-quinones, such as benzo (h) quinolinc-5, 6-quinone (I) has been carried out,> ielding the photoproducts listed in Table I. A similar photo-reaction takes place between benzo (h) quinoline-5, 6- quinone monoimine and aromatic aldehydes, yielding colorless products believed to have structurc such as 5'.(cf. Table 11) 2-~-Methoxyphenylbenzo (h) quinoline-oxazole(VII, R= ...