Production of acetic anhydride

US4333884A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Hans-Klaus Kubbeler · Rheinbach, DE
• Heinz Erpenbach · Cologne, DE
• Klaus Gehrmann · Lechenich, DE
• Klaus Schmitz · Munich, DE

Key dates

• Filing date: Sep 29, 1980
• Grant date: Jun 8, 1982
• Expiry date: Sep 29, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/56
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to an improved process for making acetic anhydride by reacting methyl acetate and/or dimethylether with carbon monoxide under practically anhydrous conditions, at temperatures of 350 to 575 K., under pressures of 1 to 300 bars, and in the presence of a catalyst system containing noble metals belonging to group VIII of the periodic system of the elements, or compounds thereof, iodine and/or its compounds, and an aliphatic carboxylic acid having 1 to 8 carbon atoms. The improved process is effected in the presence of a catalyst system containing, as additional ingredients, a heterocyclic aromatic compound, in which at least one hetero atom is a quaternary nitrogen atom, or a quaternary organophosphorus compound, and a zirconium compound being soluble in the reaction mixture.