material at that time the cell circuit is disconnected and the quinone methide isolated and separated this may be accomplished by a two step process in which the solvent solution is removed from the quinone methide ddqh 2 and ddq by evaporation the quinone methide may then be separated from the ddqh 2 and ddq by dissolving it in a solvent which is a non solvent for ddqh 2 or ddq for example quinone methide can be separated from ddq and ddqh 2 by dissolving the quinone methide in methylene chloride filtering out the still solid ddq or ddqh 2 and then re precipitating the quinone methide this example illustrates the preparation of the quinone methide of bis 3 5 dimethyl 4 hydroxyphenyl methane a divided batch electrochemical cell was fitted with platinum working and auxiliary electrodes and a saturated calomel reference electrode sce the cathode auxiliary compartment was filled with an electrolyte solution which contained 0 25m sodium acetate dissolved in one part by volume of acetic acid and four parts of acetonitrile the anode working compartment was charged with one volume of water and then filled with five volumes of the electrolyte solution to which had been added 40 g bis 3 5 dimethyl 4 hydroxyphenyl methane and 36 g ddqh 2 per liter of electrolyte to give a 10 ml solution the anode was then biased to 0 75 volts vs sce the electrolysis was continued for 148 minutes at which time current integration showed that there had passed 2 faradays of charge per mole of bis 3 5 dimethyl 4 hydroxyphenyl methane in the anode compartment at that time the cell circuit was disconnected gas chromatographic analysis of the anolyte revealed essentially complete conversion of bis 3 5 dimethyl 4 hydroxyphenyl.