Process for preparing p-benzoquinone diketals

US4046652A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Rudolf Pistorius
• Hans Millauer · Eschborn, DE

Key dates

• Filing date: Dec 19, 1975
• Grant date: Sep 6, 1977
• Expiry date: Dec 19, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25B3/23
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

P-Benzoquinone diketals of the formula ##STR1## wherein R is H, an alkyl group having from 1 to 4 carbon atoms or a halogen atom, preferably H, CH.sub.3, Cl or F, are prepared by anodic oxidation of benzene or alkoxybenzenes of the formula ##STR2## wherein R has the aforesaid meaning and R.sup.1 is an alkyl radical having of from 1 to 4 carbon atoms In CH.sub.3 OH containing PA1 A. less than about 5% by weight of H.sub.2 O as well as PA1 B. about 0.2 to 15% by weight, calculated on the electrolyte, of at least a conducting salt selected from the group of ammonium and alkali fluorides, perchlorates, nitrates, tetrafluoroborates, hexafluorosilicates, hexafluorophosphates, benzene sulfonates, p-toluene sulfonates, quartenary ammonium and phosphonium fluorides as well as methylsulfates and additionally PA1 C. optionally about 0.5 to 10% by weight, calculated on the electrolyte, of a base to be oxidized with difficulty, preferably 2,6-lutidine, At a known anode made of a conventinal material, at a temperature of from about -20.degree. to +60.degree. C. When using as starting material an alkoxybenzene wherein the group OR.sup.1 contains an alkyl radical having of from 2 to 4 carbon atoms…