Electrophilic aromatic substitution. Part 24. The nitration of isopropylbenzene, 2- and 4-isopropyltoluene, 1-chloro-4-isopropylbenzene, 4-isopropylanisole, and 2-bromotoluene: nitrodeisopropylation
作者:Ajay K. Manglik、Roy B. Moodie、Kenneth Schofield、Geoffrey D. Tobin、Robert G. Coombes、Panicos Hadjigeorgiou
DOI:10.1039/p29800001606
日期:——
The kinetics and products of nitration in aqueous sulphuric acid of the title compounds have been studied. 4-Isopropyl-phenol and -anisole are nitrated at or near the encounter rate. In 65–79% H2SO4 2-isopropyltoluene suffers ca. 25%ipso-attack; the only fate of WiPri(ipso-Wheland intermediate) is nitrodeisopropylation. From 4-isopropyltoluene WiPri is also nitrodeisopropylated, but some 1,2-nitro-migration
研究了标题化合物在硫酸水溶液中硝化的动力学和产物。将4-异丙基苯酚和-茴香醚以相遇率或相近的速率进行硝化。在65-79%的H 2 SO 4 2- isopropyltoluene患有约 25%ipso-攻击;W的唯一命运我镨我(本位-Wheland中间体)是nitrodeisopropylation。从4-异丙基甲苯W i Pr i也被硝基异异丙基化,但是可能发生一些1,2-硝基迁移。来自同一化合物W i Me可能被水捕获,重排或产生4-甲基苯乙酮; 提出了形成最后化合物的机制。硝基去异丙基化在没有水的帮助下发生。对于4-异丙基茴香醚,脱去甲氧基化和硝基去异丙基化是W i Pr i形成的结果。该结果与通过增加两个酸度而增加酸度对C-4的攻击,在没有水的帮助下失去异丙基,以及未观察到的中间体4-异丙基-4-硝基环己-2,5-二烯酮的分解相一致。一种酸催化的方法得到4-硝基苯酚和可能的4-异丙