Process for the manufacture of cyclohexane-1,3-diones and 6-alkyl-3,4-dihydro-2-pyranones

US4041049A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Werner Muller · East Greenwich, US
• Hansjorg Hey · Hofheim, DE
• Helmut Meidert · Frankfurt am Main, DE

Key dates

• Filing date: Oct 10, 1975
• Grant date: Aug 9, 1977
• Expiry date: Oct 10, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C49/657
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Cyclohexane-1,3-diones of the formula ##STR1## having up to 24 carbon atoms are prepared in admixture with 6-alkyl-3,4-dihydro-2-pyranones of the formula ##STR2## having up to 24 carbon atoms, in which formulae the radicals R and R' may be identical or different and represent each a hydrogen atom, an alkyl, a cycloalkyl or an aryl group each having up to 12 carbon atoms and the two radicals R' together optionally represent a --(CH.sub.2).sub.3 -group, by passing 4-oxocarboxylic acids of the formula ##STR3## having up to 24 carbon atoms and in which R and R' have the above meaning at a temperature of from 250.degree. to 500.degree. C in the gaseous phase over a dehydration catalyst and the pyranones are converted into cyclohexane-1,3-diones by passing them in the gaseous phase over a dehydration catalyst at a temperature of from 250.degree. to 500.degree. C.