Preparation of substituted phenols

US4538009A · kind A · utility

Assignee

• BASF SE

Inventors

• Norbert Goetz
• Harald Laas · Frankenthal (Pfalz), DE
• Peter Tavs · Schifferstadt, DE
• Leopold Hupfer · Friedelsheim, DE
• Karl Baer · Weinheim, DE

Key dates

• Filing date: Apr 12, 1984
• Grant date: Aug 27, 1985
• Expiry date: Apr 12, 2004

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C37/06
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Substituted phenols of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each hydrogen or an aliphatic or aromatic hydrocarbon radical, are prepared by dehydrogenating a cyclic alcohol of the general formula II ##STR2## or a cyclic ketone of the general formula III ##STR3## where one of the broken lines can be an additional C-C bond, in the gas phase at from 150.degree. to 380.degree. C. over a supported noble metal catalyst, by a process in which the dehydrogenation catalyst used is palladium or platinum on an aluminum spinel carrier, in particular an aluminum spinel which has a BET specific surface area of from 5 to 150 m.sup.2 /g or, for the dehydrogenation of cyclohexenones, preferably from 10 to 50 m.sup.2 /g. Particularly suitable aluminum spinels are those which, in addition to aluminum, contain magnesium, zinc, cobalt or nickel. In the novel process, substituted phenols are obtained in high yields and selectivities, and the catalyst has an extremely long life without a significant decrease in activity.