卤锂交换法合成苯基三甲氧基硅烷的研究

Study on Synthesis of Phenyltrimethoxysilane by Halide Lithium Exchange

以正丁基锂和溴苯为原料通过卤锂交换法合成了苯基锂,再采用苯基锂与四甲氧基硅烷进行亲核取代反应合成了苯基三甲氧基硅烷,分别探讨了苯基锂和苯基三甲氧基硅烷合成的影响因素,并采用红外光谱和核磁共振波谱表征了产物结构。结果表明,卤锂交换法合成苯基锂的较佳条件为溶剂选择正丁醚和四氢呋喃,溶剂与正丁基锂溶液的体积比为1∶2,反应时间2 h,正丁基锂滴加速率2 mL/min;苯基三甲氧基硅烷合成的较佳条件为苯基锂合成时的溶剂选择正丁醚,亲核取代反应溶剂选择四甲氧基硅烷,四甲氧基硅烷用量与正丁基锂体积比为3∶1,反应温度0~20℃,反应时间为1 h,苯基锂滴加速率1.5~2 mL/min,此时苯基三甲氧基硅烷的收率为78%。

Phenyllithium was synthesized by halogenated lithium exchange from n-butyllithium and bromobenzene, and then phenyltrimethoxylsilane was synthesized by nucleophile substitution reaction between phenyllithium and tetramethoxylsilane. The influencing factors of the synthesis of phenyllithium and phenyltrimethoxylsilane were discussed respectively, and whose structure was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The results show that the optimal conditions for the synthesis of phenyllithium by halogenated lithium exchange are that n-butyl ether and tetrahydrofuran is as solvent, the volume ratio to n-butyl lithium solution is 1∶2, the reaction time is 2 h, and drop rate of n-butyl lithium is 2 mL/min. The optimal conditions for the synthesis of phenyltrimethoxylsilane are that n-butyl ether as the solvent during the synthesis of phenyllithium, tetramethoxylsilane is used as the nucleophilic substitution solvent, and the volume ratio of tetramethoxylsilane to n-butyl lithium is 3∶1, the reaction temperature is 0-20 ℃, the reaction time is 1 h, the drop rate of phenyl lithium drop is 1.5-2 mL/min, and the yield of phenyl trimethoxylsilane is 78%.