860. ------. [GREESHAM, W. F., AND BROOKS, R. E.] (E. I. du Pont de Nemours & Co.). Anhydride Synthesis. United States Patent 2,549,453, Apr. 17, 1951. Chem. Abs., vol. 45, 1951, p. 8551.

Patent Abstracts

Organic carboxylic acid anhydrides are prepared from olefins with CO and carboxylic acids or substances that yield carboxylic acids. EtCO₂H (I), 74:Ni(CO)₄, 10: and C₂H₄, 28 gm. heated 15 min. in a Cu-lined pressure-resistant vessel with CO at 272º-293º under 600-810 atm. gave 39% conversion to (EtCO)₂O (II). H₂O, 18: Ni(CO)₄, 5: and C₂H₄, 56 gm. with CO at 280º and 800 atm. gave a liquid containing (II). CO. 0.5: C₂H₄ 0.36: (I). 1.0: and Ni(CO)4, 0.11 mole passed through a Cu-lined converter at 263º under 605 atm. with a contact time of 4.9 min. gave 183 lb. per cu. ft. per hr. of (II).