| 摘要 |
Esters of carboxylic acids are obtained by reacting under pressure at 100-325 DEG C., preferably 200-300 DEG C., an alcohol, or an ether, or a mixture thereof, with carbon monoxide, in the presence of a cobalt or nickel salt of an aliphatic organic mono-carboxylic acid as catalyst. Pressures instanced range from 200 to 1500 atms., and are preferably 400 to 1000 atms. The presence of hydrogen favours the reaction and quantities of catalyst used range from 2 to 10 per cent based on the total weight of the liquid reaction mixture. Alcohols specified are ethanol, isopropanol and methanol, which is preferred. Ethers specified are dialkyl ethers. When methanol is treated the hydrogen and carbon monoxide required may be obtained in situ by the decomposition of further quantities of methanol and in the production of methyl acetate from methanol the concentration of carbon monoxide to hydrogen is in a molar ratio of 3 to 1. In examples: (1) and (2) methanol is treated at elevated temperatures and under pressure with carbon monoxide and water in the presence of cobalt acetate as catalyst to yield methyl acetate; (3) and (6) are similar except that the reaction is effected in the presence of added hydrogen and in one instance in (6) dimethyl ether is also present; and in (4) and (5) dimethyl ether is treated at elevated temperatures and under pressure with carbon monoxide and water in the presence of iodine as reaction promoter and nickel acetate as catalyst obtained in situ by the decomposition of nickel carbonyl to give methyl acetate and acetic acid. |
