【摘要】 通过实验及动力学研究,证明-3巯基香豆素(6)和二苯胺发生α-氨甲基化反应时,是(6)首先和甲醛反应,生成S-半缩醛——3-羟甲硫基香豆素(7),然后再与二苯胺反应形成3-二苯胺甲硫基香豆素(8),3-羟甲硫基香豆素与二苯胺在冰醋酸的催化作用下进行反应时,随着酸浓度的改变,反应机理发生了改变,本文对这一反应机理进行了讨论和解释。更多还原

【Abstract】 A kinetic study of the Mannich reaction of 3-thiolcoumarin with diphenylaminewas studied. It was found that the mechanism of this reaction is different from theclassical mechanism of Mannich reaction. 3-Thiolcoumarin first condenses with form-aldehyde to produce 3-hydroxy-methylthiocoumarin which then reacts with diphenyl-amine with the formation of the a-aminomethylated thioether. The reaction appearsto be third order at low concentrations (below 0.2 mol.L^-1) and first order at high-er concentrations(above 0.35 mol. L^-1) of the acetic acid used in the acid catalysis.更多还原