2,6-Dimethyl-1,4-benzoquinone

Experimental procedure: under argon atmosphere, a secondary alcohol (0.66 mmol) and 1 (0.66 mmol) in 1,2-dichloroethane (0.6 mL) are stirred for 7.0 h at 100 °C. To a mixture of benzoic acid (0.60 mmol) and 2,6-dimethyl-1,4-benzoquinone (0.6 mmol) is added the above reaction solution. The reaction is stirred for 1.0 h at room temperature and is quenched by adding water after completion of the reaction. The aqueous layer is extracted with dichloromethane. The combined organic layer is washed with brine and dried over anhydrous sodium sulfate. After filtration and evaporation, the resulting residue is purified by preparative TLC to afford the corresponding esters.