Aromatic isomerizations and related reactions. Part 6 Reactions of the tetra- and pentamethylbenzenesulfonic acids and hexamethylbenzene in concentrated sulfuric acid; the mechanism of the Jacobsen reaction
作者:Ankie Koeberg-Telder、Hans Cerfontain
DOI:10.1002/recl.19871060304
日期:——
and the three tetramethylbenzenes (TeMB's) in concentrated aqueous sulfuric acid has been studied quantitatively using 1H and 13C NMR and UV spectroscopy. PMB-sulfonic acid yields (protonated) hexamethylbenzene (HMB) and the 2,3,4,5- and 2,3,4,6-TeMB-1-sulfonic acids in an initial ratio of 9/1/8 up to a substrate conversion of 36%; the ratio of HMB to the TeMB-1-sulfonic acids remains 1/1 and the only
使用1 H和13 C NMR和UV光谱定量研究了五甲基苯(PMB)和三个四甲基苯(TeMB's)在浓硫酸水溶液中的化学行为。PMB磺酸以9/1/8的初始比例生成(质子化)六甲基苯(HMB)和2,3,4,5-和2,3,4,6-TeMB-1-磺酸底物转化率为36%;HMB与TeMB-1-磺酸的比率仍为1/1,唯一的后续反应是2,3,4,6-相对缓慢地转化为2,3,4,5-TeMB-1-磺酸是浓硫酸中唯一稳定的TeMB-1-磺酸异构体。