A careful re-examination of the arylation (P. Brassard and P. L'Écuyer. Can. J. Chem. 36, 814 (1958)). reaction with chlorobenzoquinone has revealed in its products the presence of all the three possible disubstituted isomeric quinones. Arylation using diazotized p-nitro- aniline has resulted in the isolation of the three new isomeric quinones, whose structures are assigned, based on chemical and spectral evidences. Mechanistic implications in the ...