Method for the production of 2-coumarone and substituted 2-coumarones

US6858743B2 · kind B2 · utility

Assignee

• DSM Fine Chemicals Austria NFG GmbH & Co KG · AT

Inventors

• Michael Stanek · San Clemente, US
• Peter Hildebrand · Pfronten, DE
• Curt Zimmermann · Ansfelden, AT
• Marianne Castelijns · Spaubeek, NL

Key dates

• Filing date: May 9, 2001
• Grant date: Feb 22, 2005
• Expiry date: Sep 15, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D307/83
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the production of 2-coumarone or substituted 2-coumarones, whereby cyclohexanone or substituted cyclohexanone is reacted with a carboxyl-containing acylating agent a) to give methyl 2-(2-oxo-cyclohexyl)-2-hydroxyacetate or substituted methyl 2-(2-oxo-cyclohexyl)-2-hydroxyacetates, which are either a1) directly converted to 2-coumarone or substituted 2-coumarones by means of catalytic gas-phase dehydrogenation, or a2) dehydrated by means of azeotropic distillation under basic conditions, or by use of a strong acid, or a strongly acidic ion exchanger to a mixture of methyl 2-oxocyclohexylidenacetate and the enol-lactone of the 2-oxocyclohexylidenacetic acid, or a mixture of substituted methyl 2-oxocyclohexylidenacetate and the enol-lactone of the substituted 2-oxocyclohexylidenacetic acid, which is finally converted in turn by catalytic gas-phase dehydrogenation to 2-coumarone, or substituted 2-coumarones, or b) are directly converted under acidic or basic conditions into a mixture of methyl 2-oxocyclohexylidenacetate and the enol-lactone of 2-oxo-cyclohexylidenacetic acid, or a mixture of substituted methyl 2-oxocyclohexylidenacetate and the eno…