Process for the preparation of camphene by the rearrangement of a-pinene

US5826202A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Manfred Gscheidmeier · Gablingen, DE
• Harald Haberlein · Gersthofen, DE
• Hans Haberlein · Neu-Ulm, DE
• Jorg Thomas Haberlein, heir · Allersberg, DE
• Mark Christian Haberlein, heir · Glückstadt, DE

Key dates

• Filing date: Nov 25, 1996
• Grant date: Oct 20, 1998
• Expiry date: Nov 25, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2602/42
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for the preparation of camphene by the rearrangement of .alpha.-pinene A process for the preparation of camphene by the rearrangement of .alpha.-pinene in the presence of a titanium oxide hydrate catalyst under the action of heat, wherein .alpha.-pinene is refluxed until the content of .alpha.-pinene in the reaction mixture is still at least 3% by weight, and the rearrangement is then brought to completion in a secondary reaction at a temperature below 160.degree. C. By carrying out the process in this way--refluxing to a relatively high residual content of .alpha.-pinene and performing a secondary reaction at a lower temperature--the formation of polymeric by-products is reduced. This process moreover increases the yield of camphene in that recycled tricyclene, concentrated in the distillation of the crude product, is partially rearranged to camphene or the formation of more tricyclene is reduced.