Process for the preparation of 3,5,5-trimethylcyclohexa-3-en-1-one (.beta.-isophorone) by isomerization of 3,5,5- trimethylcyclohexa-2-en-1-one (.alpha.-isophorone)

US6265617A · kind A · utility

Assignee

• Degussa-Huels AG · DE

Inventors

• Steffen Krill · Mühltal, DE
• Stephan Kretz · Bad Orb, DE
• Hans Joachim Hasselbach · Gelnhausen, DE
• Klaus Huthmacher · Gelnhausen, DE
• Rainer Hahn · Tübingen, DE
• Hermann Schmitt · Rodenbach, DE

Key dates

• Filing date: May 13, 1999
• Grant date: Jul 24, 2001
• Expiry date: May 13, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C45/82
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of 3,5,5-trimethylcyclohexa-3-en-1-one (.beta.-isophorone) by isomerization of 3,5,5-trimethylcyclohexa-2-en-1-one (.alpha.-isophorone) in the liquid phase in the presence of a salt-like or organometallic catalyst. By using catalytic quantities of alkali-metal salts or alkaline-earth salts and/or their organometallic compounds, and without addition of a further auxiliary substance, the space-time yield in the preparation of .beta.-isophorone is high. .beta.-Isophorone is particularly suitable as an intermediate product for the preparation of ketoisophorone.