PhOH/PhNH2 to benzoquinone w/MnO2 - 95%

[psyloxy]

J.Org.Chem.USSR - 26,11.1990;2127

1,4-Benzoquinone

To a mixture of 8g pyrolusite (78% MnO2) and 150 mL of % sulfuric acid, cooled to 10°C, we added dropwise with stirring over 2h 2,5g of phenol, 2,5g aniline, and 30ml of 30% sulfuric acid. At the same time we added 48g of pyrolusite to the reactor (in 6g portions at 15 min intervals). The obtained mixture was kept at the same temperature for a further 1.5h, and the reaction product was extracted with diethyl ether (50 x 2 mL ^{typo ?} ). The yield of 1,4-benzoquinone was 5.4g (95%).

--psyloxy--