Process for the preparation of 1,4-3,6-dianhydro-hexitols

US4408061A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Herbert Salzburg · Leichlingen, DE
• Holger Meyborg · Odenthal, DE
• Heinz Ziemann · Leichlingen, DE

Key dates

• Filing date: Mar 11, 1982
• Grant date: Oct 4, 1983
• Expiry date: Mar 11, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D493/04
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of 1,4-3,6-dianhydro-hexitols from hexitols by elimination of water is described, characterized in that gaseous hydrogen halide is used as the acid dehydrating agent optionally with carboxylic acids, carboxylic acid halides and/or carboxylic acid anhydrides in quantities of up to 600 mol percent, based on the hexitols, as cocatalysts. The reaction is carried out in the absence of water and organic solvents, preferably using gaseous hydrogen chloride, temperatures of up to 300.degree. C. and pressures of up to 250 bar. Very high yields are obtained after working up of the product by distillation or extraction.