Polymerisation and related reactions involving nucleophilic aromatic substitution. Part 1. The rates of reaction of substituted 4-halogenobenzophenones with the potassium salts of substituted 4-hydroxybenzophenones
作者:John H. Ridd、Taher I. Yousaf、John B. Rose
DOI:10.1039/p29880001729
日期:——
s by the potassium salts of 4′-X,4-hydroxybenzophenones (X = CF3, Cl, F, H, OPh, and OMe) has been studied at 175–225 °C in diphenyl sulphone as solvent. Comparison with the corresponding rate of displacement of chlorine indicates that the reaction is a bimolecular nucleophilic aromatic substitution. The reaction obeys the Hammett equation using normal σ values for substitution in both the substrate
在175处研究了4'-X,4-羟基二苯甲酮的钾盐(X = CF 3,Cl,F,H,OPh和OMe)从4'-X,4-氟二苯甲酮中置换氟的速率。在二苯砜中为–225°C作为溶剂。与相应的氯置换速率的比较表明该反应是双分子亲核芳族取代。在底物(ρ1.19)和酚盐(ρ–0.53)中,反应均使用正常的σ值遵守Hammett方程。盐对反应速率的影响也很明显,它已包含在取代基常数中,作为计算速率系数的通用方程式。O的影响– 取代基的显着性要比该取代基的先前σ值范围所期望的要大。