with 2,5-dimethyl-p-benzoquinone (2a) or 2,6-diisopropyl-p-benzoquinone in various solvents at 20°C were determined by spectrophotometric method. The rate of 1 and 2a in ethanol : water=60 : 40 solution was 5.55×102 dm3 mol−1 s−1, which was fourteen folds of that in chloroform (3.9×10−3 dm3 mol−1 s−1). This solvent effect and the low solubility of the cycloadduct in aqueous ethanol were successfully applied
2,6-二
氯苄腈 N-氧化物 (1) 与 2,5-二甲基-对-苯醌 (2a) 或 2,6-二异丙基-对-苯醌的 1,3-偶极环加成反应的二级速率常数各种溶剂在 20°C 下用分光光度法测定。1和2a在
乙醇:
水=60:40溶液中的比例为5.55×102 dm3 mol-1 s-1,是
氯仿中的14倍(3.9×10-3 dm3 mol-1 s-1)。这种溶剂效应和环加合物在
乙醇水溶液中的低溶解度被成功地应用于环加合物的合成。