PURPOSE: To prepare the titled substance useful as a raw material of pesticides, etc., economically, in an industrial scale, by oxidizing 1,4,4a,9a-tetrahydroanthraquinone, etc. with molecular oxygen in a solvent using an organic acid such as aromatic sulfonic acid in place of a base as a catalyst.
CONSTITUTION: The titled compound is prepared by oxidizing 1,4,4a,9a-tetrahydroanthraquinone or 1,4-dihydroanthraquinone with molecular oxygen, in a polar organic solvent pref. acetic acid or ethanol, in the presence of an organic acid having a pK value of about ≤1 as a catalyst, pref. at 20W100°C. The catalyst is pref. an aromatic sulfonic acid such as benzenesulfonic acid, etc., or an aliphatic sulfonic acid such as methanesulfonic acid, etc. The amount of the catalyst is 0.01W 5%, pref. 0.02W2% of the solvent.
SOUBE KOUJI
HATA KEISHIROU
KASEDA MIKIO
