Method for manufacturing p- and o-benzoquinone derivatives

A method for synthesizing p- or o-benzoquinone derivatives represented by formula III or IV ##STR7## by oxidizing, at a temperature between -20.degree. C. and 35.degree. C., in the presence of a quaternary ammonium salt phase transfer catalyst, with an aqueous hypohalite solution having a pH of from 8 to 10, a p- or o-hydroquinone derivative represented by formula I or II ##STR8## wherein, in formula I, II, III, and IV, R.sub.1 through R.sub.8, which may be the same or different, represent hydrogen atoms, or alkyl or aryl groups, provided that all the R.sub.1, R.sub.2, R.sub.3 and R.sub.4 groups and all the R.sub.5, R.sub.6, R.sub.7 and R.sub.8 groups are not hydrogen atoms, and R.sub.1 and R.sub.2, R.sub.3 and R.sub.4, R.sub.5 and R.sub.6, and R.sub.6 and R.sub.7, respectively, may form a 5 or 6-membered hydrocarbon ring, said temperature being between 0.degree. C. and 35.degree. C. when a compound of formula I is oxidized and between -20.degree. C. and 0.degree. C. when a compound of formula II is oxidized.