Method for the continuous production of unsaturated carboxylic acid anhydrides

US7714165B2 · kind B2 · utility

Assignee

• Evonik Röhm GmbH · DE

Inventors

• Dirk Broell · Langen, DE
• Hermann Siegert · Weiterstadt, DE

Key dates

• Filing date: Mar 14, 2007
• Grant date: May 11, 2010
• Expiry date: Mar 14, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/567
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the continuous production of unsaturated carboxylic acid anhydrides of general formula (I): R—C(O)—O—C(O)—R (I), wherein R is an unsaturated organic group with 2 to 12 C atoms, by reaction of a ketene with an unsaturated carboxylic acid of general formula (II): R—COOH (II), wherein R is defined as above, in an apparatus which has a reaction zone (1) for the reaction of a ketene with an unsaturated carboxylic acid of general formula (II), and a reaction zone (2) for the subsequent reaction of the crude anhydride mixture and a rectification column with an upper, a middle and a lower zone, in the sump of which an inert boiling oil is present.