1,4-Di-o-tolyl-2,3-naphthoquinone

1,4-Di-o-tolyl-2,3-naphthoquinone (1), produced by lead tetra-acetate oxidation of 1,4-di-o-tolylnaphthalene-2,3-diol (7) at –30 °C is sufficiently stable to allow purification involving aqueous work-up and low temperature chromatography; it has been characterised by u.v. and i.r. spectroscopy, as the adduct (8) formed with norbornadiene, and by a comparison of its properties with those of the stable quinone (9).