Preparation of phthalides

US5296614A · kind A · utility

Assignee

• BASF SE

Inventors

• Jochem Henkelmann · Mannheim, DE
• Thomas Ruehl · Bischofswerda, DE
• Horst Zimmermann · Mannheim, DE

Key dates

• Filing date: Oct 30, 1992
• Grant date: Mar 22, 1994
• Expiry date: Oct 30, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D307/88
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of phthalides of the formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another, are hydrogen, C.sub.1 - to C.sub.4 -alkyl or C.sub.1 - to C.sub.4 -alkoxy, by reacting phthalic anhydrides of the formula II ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined as above, on hydrogenation catalysts at from 50.degree. to 400.degree. C. and at from 1 to 400 bar, wherein the hydrogenation catalysts employed are essentially free from Lewis acids.