丁二烯副产物4-乙烯基环己烯的1,2-环氧化反应

研究了用碳酸钠调节反应体系的pH,以30%(质量分数,下同)过氧乙酸为氧化剂,氧化4-乙烯基环己烯(4-VCH)合成4-乙烯基-1,2-环氧环己烷的情况。探讨了碳酸钠的添加方式、反应温度、反应时间及过氧乙酸用量等因素对4-乙烯基-1,2-环氧环己烷收率的影响。实验结果表明,通过在反应体系中加入碳酸钠可有效提高4-乙烯基-1,2-环氧环己烷的收率;同时加入碳酸钠和过氧乙酸,可维持反应体系的弱酸性,有利于4-乙烯基-1,2-环氧环己烷的生成;合成4-乙烯基-1,2-环氧环己烷较适宜的条件为:乙酸乙酯200mL、碳酸钠20.0g、30%过氧乙酸90mL、4-VCH50mL、反应温度45℃、反应时间2.0h;在此条件下,4-乙烯基-1,2-环氧环己烷的收率为85%(以4-VCH为基准),4-乙烯基-1,2-环氧环己烷的纯度达99%。

Epoxidation of 4-Vinyl-Cyclohexene from Byproducts of Butadiene Production

Epoxidation of 4-vinyl-cyclohexene(4-VCH) to 1,2-epoxide-4-vinyl-cyclohexane with 30%(mass fraction) peroxyacetic acid as oxidant was studied. The yield increases by adding sodium carbonate to adjust pH of reaction system. Effect of different addition modes of sodium carbonate on yield of the product was carefully observed. To keep a weak acidic reaction system by adding sodium carbonate and peroxyacetic acid at the same time favors the increase of product yield. Effects of other factor, such as reaction time, reaction temperature and the ratio of reactants etc. on yield of 1,2-epoxide-4-vinyl-cyclohexane were also studied. Under optimum reaction conditions: acetic ester 200 mL,sodium carbonate 20.0 g, 30% peroxyacetic acid 90 mL, 4-VCH 50 mL, reaction temperature 45 ℃ and reaction time 2.0 h, yield and purity of 1,2-epoxide-4-vinyl-cyclohexene can reach 85% (based on 4-VCH) and 99%, respectively.