| 摘要 |
1,235,185. Preparation of unsaturated esters of carboxylic acids. FARBENFABRIKEN BAYER A.G. 7 June, 1968 [11 July, 1967; 29 March, 1968; 15 Feb., 1968], No. 27216/68. Heading C2C. A process for producing unsaturated esters of carboxylic acids comprises catalytically reacting olefins with organic acids and oxygen at elevated temperature and at normal or elevated pressure, wherein most of the carboxylic ester formed, the acids and water are separated by cooling from the reaction products leaving the reactor, and the uncondensed components are recycled either wholly or in part to the inlet of the reactor, the recycled gas from which the condensed components have been removed being washed before it enters the reactor with a liquid organic solvent boiling at a higher temperature than the unsaturated ester formed. Examples describe the preparation of vinyl acetate from ethylene, oxygen and acetic acid using a catalyst comprising palladium, gold and potassium acetate on a silicic acid support. The liquid organic solvent may be an oxygen-containing compound of the glycol type, or an ether or ester thereof or may be the same carboxylic acid as that used to prepare the unsaturated ester. |
