| 摘要 |
Monocarboxylic aliphatic acids and esters thereof are produced from monohydric aliphatic alcohols containing one carbon atom less per molecule than the acid formed by reacting the alcohols with carbon monoxide or carbon monoxide-containing gas under pressure and at elevated temperature in the presence of catalysts consisting of at least one silver halide or of silver or at least one silver halide in the presence of at least one other metal halide. Preferably the other metal halides used are those of the alkalie earth metals or of heavy metals, e.g. potassium iodide and nickel chloride. Carbon monoxide may be used in a mixture with hydrogen or with small quantities of carbon dioxide. The reaction may be carried out at such a temperature that the starting materials and the products are in the gaseous phase and in this case the catalyst should be applied to a carrier, e.g. activated charcoal, copper or the like. Normally certain quantities of ethers and esters are obtained in addition to the acids but the formation of these is inhibited if a carrier having a dehydrating action is used. The formation of ethers and esters may also be reduced by isolating them as they are formed and returning them to the cycle. Preferably a temperature above 250 DEG C. and a pressure over 100 atm. is used. Water may be present in the reaction mixture. In the examples acetic acid and methyl acetate are obtained from methyl alcohol and carbon monoxide with (a) silver iodide; (b) silver bromide; (c) potassium iodide, silver chloride and silver iodide; (d) potassium iodide, nickel chloride and metallic silver, as catalysts. |
