4,4,5,5,5-五氟戊醇的合成

摘要

报道了以五氟丙酸乙酯和乙酸乙酯为起始原料,经克莱森缩合、氯化、氢化及还原等4步反应合成4,4,5,5,5五氟戊醇的新工艺.通过正交实验优化了克莱森缩合反应工艺条件,并对其他三步反应工艺条件进行了考察.优化的工艺条件为:克莱森反应温度50℃,反应时间2h,n(五氟丙酸乙酯)∶n(乙酸乙酯)∶n(NaH)=1∶1.3∶1.3;氯化亚砜在50℃反应;雷尼镍和三乙胺在室温反应;硼氢化钠和三氟化硼四氢呋喃溶液在8～12℃反应.在此条件下,4步反应总收率为75.5％,纯度98.5％.%4,4,5,5,5-Pentafluoropentan-1-ol was synthesized from the ethyl 2,2,3,3,3-pentafluoropropanoate and ethyl acetate via claisen condensation,chlorination,hydrogenation and reduction. The claisen condensation condition was determined by orthogonal test,and the other steps were optimized.The claisen condensation conditions were as follows:the molar ratio of ethyl 2,2,3,3,3-pentafluoropropanoate to ethyl acetate and sodium hydride was 1 ∶ 1.3 ∶ 1.3,and reacted at 50 ℃ for 2 h.The other steps were as follows:chlorination for sulfoxide chloride at 50 ℃,hydrogenation for Raney Ni and triethylamine at room temperature,reduction for sodium borohydride and trifluoroborane at 8-12 ℃.After optimization,the total yield of the four steps was 75.5％ with purity of 98.5％.