KINETIC STUDY OF STILBENE SYNTHESIS VIA THE REACTION OF BENZYLTRIPHENYLPHOSPHONIUM CHLORIDE WITH BENZALDEHYDE IN A TWO PHASE SYSTEM
KINETIC STUDY OF STILBENE SYNTHESIS VIA THE REACTION OF BENZYLTRIPHENYLPHOSPHONIUM CHLORIDE WITH BENZALDEHYDE IN A TWO PHASE SYSTEM
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DOI：
10.1080/00986448908940036
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发表时间：
1989-05
影响因子：
2.5
通讯作者：
Maw‐Ling Wang;Chun-Jen Lin;Jing-Jer Jwo
中科院分区：
文献类型：
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作者：
Maw‐Ling Wang;Chun-Jen Lin;Jing-Jer Jwo
本文研究了苯甲醛（C6 H5 CHO）与苄基三苯基氯化膦（BTPPC）在NaOH（aq）/-CH_2Cl_2两相体系中合成二苯乙烯的Wittig反应动力学，反应速率取决于搅拌速度、温度、C6 H5 CHO、BTPPC和NaOH的浓度。当搅拌速度小于200 rpm时，反应速率由扩散控制。当搅拌速度大于600 rpm时，达到两相的均匀混合。动力学数据表明，反应速率与NaOH和BTPPC浓度呈线性关系，与C6 H5 CHO浓度呈渐近关系。反应非常迅速，即使在0°C下也能在几分钟内完成。二苯乙烯的收率可达95%以上。芪产物中的顺式与反式异构体之比约为2，与反应物浓度和温度无关。一个简化的反应机理提出了合理的动力学数据。
Abstract The kinetic study of the Wittig reaction of synthesizing stilbene is carried out by reacting benzaldehyde (C6H5CHO) with benzyltriphenylphosphonium chloride (BTPPC) in the NaOH (aq)/-CH2C12 two-phase system, the rate of reaction depends on the agitating speed, temperature, and the concentration of C6H5 CHO, BTPPC, and NaOH. When the agitating speed is less than 200 rpm, the reaction rate is controlled by diffusion. Uniform mixing of two phases is reached when the agitating speed is greater than 600 rpm. The kinetic data indicated that the reaction rate depends linearly on the concentrations of NaOH and BTPPC and asymptotically on C6H 5CHO concentration. The reaction is very rapid and is complete within a few minutes, even at 0°C. The yield of stilbene as high as 95% can easily be obtained. The cis- to trans-isomer ratio in the stilbene product is about 2, independent of reactant concentrations and temperature. A simplified reaction mechanism is proposed to rationalize the kinetic data.