论文部分内容阅读
利用对位异构体的对称性由核磁共振氢谱测定了工业十二烷基苯在硝硫混酸中的硝化选择性，发现一硝化产物中对位异构体的比例为７５％～８０％。以月桂酸和苯为原料，经氯化、酰化和还原合成了正十二烷基苯。在同样条件下研究了正十二烷基苯的硝化，由核磁共振氢谱和气相色谱分析，发现一硝化产物中对位异构体的比例仅为６０％。根据空间位阻效应，对结果进行了讨论，并与甲苯，乙苯，异丙苯等短链烷基苯的硝化结果进行了比较。
The selectivity of nitration of industrial dodecylbenzene in nitric-sulfur mixed acid was determined by 1H nuclear magnetic resonance (1H-NMR) spectroscopy using the symmetry of the para-isomer. The proportion of para-isomer in the mononitration product was found to be 75% -80% . Starting from lauric acid and benzene, n-dodecylbenzene was synthesized by chlorination, acylation and reduction. The nitration of n-dodecylbenzene was studied under the same conditions and was found to be only 60% of the para-isomer in the mononitration product by nuclear magnetic resonance (1H) and gas chromatography analysis. Based on the steric hindrance effect, the results were discussed and compared with the results of nitration of short-chain alkylbenzenes such as toluene, ethylbenzene and cumene.