| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an unsaturated carboxylic east in high yield with reduced formation of by products by reaction of a specific amount of an unsaturated carboxylic acid with a cyclic alcohol in the presence of a catalyst. SOLUTION: An acidic catalyst is used for carrying out the reaction of an unsaturated carboxylic acid with a cyclic alcohol where the molar ratio of the carboxylic acid to the alcohol is kept in the range from 1/1.1. to 1/1.5 at the initial stage and at 1/(8-10) at the latter stage. The unsaturated carboxylic acid is, for example, methacrylic acid, the cyclic alcohol is cyclohexanol and the acidic catalyst is p-toluenesulfonic acid. The molar ratio of the reactants are kept at a constant level to suppress the decomposition of the staring alcohol, thus increasing the selectively of the starting alcohol. The concentration of the aqueous alkali to used for neutralizing the catalyst is kept constant to prevent the recovery loss due to the phase separation whereby the yields of the product and the starting alcohol can be increased.</p> |
