固体超强碱催化环己酮羟醛缩合反应的研究

Study on aldol condensation reaction of cyclohexanone catalyzed by solid superbase

环己酮自身羟醛缩合产物2-(1-环己烯基)环己酮与2-环己亚烷基环己酮是合成柑桔类杀菌防腐剂邻苯基苯酚(OPP)的中间体,传统合成方法主要采用液体碱等均相催化剂,催化效率低且产品难以分离,为此本文以改进的Na/NaOH/-γAl2O3型固体超强碱为催化剂,探索了一种新的合成工艺,同时对反应条件进行了优化。实验结果表明:反应温度为190℃、催化剂用量为原料质量的10%、反应时间为3 h时,二聚物产率最高,达85.66%。该合成工艺催化效率高,产品易分离,后处理简单,具有一定的工业应用前景。

2-（1-Cyclohexen-l-yl） cyelohexanone and 2-cyclohexylidenecyclohexanone are the intermediates for synthesizing ophenylphenol （OPP）.They are usually prepared by means of aldol condensation catalyzed by a liquid basic catalyst, such as sodium hydroxide, sodium ethoxide and so on. However, there is no ideal yield obtained and the separation of products manufactured by these methods is quite difficult. In this paper, 2-（ 1-cyclohexen-l-yl ） cyclohexanone and 2-eyclohexylideneeyclohexanone were prepared through catalysis by a solid superbase Na/NaOH/γ-Al2O3. The factors affecting the yield of dimers were considered and the best conditions were found out. The optimum yield of dimmers, whieh could be as high as 85.66 %, was obtained when the reaction temperature was 190 ℃ and the reaction time was 3 h with the mass ratio of catalyst amounting to 10% of cyclohexanone.The synthesis method has the perspective for commercial application thanks to the high catalytic efficiency and simple after-treatment of the products.