A series of 4′-substituted 3-bromo-4-nitrobiphenyls have been prepared and the rates of piperidinodebromination in methanol at three different temperatures have been measured. The kinetic data are satisfactorily correlated by a modified Hammett relationship (ρ+ 0.35) using σp constants for 4′-halogen and σp+ 0.32(σ––σp) for strongly electron-withdrawing 4′-substituents (MeCO, MeSO2, and NO2). Comparison
已经制备了一系列的4'-取代的3-溴-4-
硝基联苯,并且已经测量了在三个不同温度下在
甲醇中
哌啶基溴化的速率。动力学数据是由改性哈米特关系令人满意相关(ρ+ 0.35),使用σ p为4'-卤素和σ常数p + 0.32(σ - -σ p)为强吸电子4'-取代基(梅科,内消旋2和NO 2)。与先前报道的在相应的3'-和4'-取代的
3-硝基-4-
溴代二苯上进行相同反应的结果进行了比较。