中文摘要：

4位取代的Hantzsch酯（HEH）衍生物在2-硝基-2-亚硝基丙烷的氧化下生成相应的吡啶类化合物.将N-氘代1,4-二氢Hantzsch酯（N-d-HEH）和4,4＇-双氘代1,4-二氢Hantzsch酯（4,4＇-2d-HEH）分别代替HEH与2-硝基-2-亚硝基丙烷反应,得到的同位素效应常数分别为1.03（kN—H/kN—D）和1.78（kC4—H/kC4—D）,表明1,4-二氢Hantzsch酯中4位上氢原子所涉及的C4—H键的断裂发生在反应的决速步骤中或在决速步骤之前,而1位上氢原子所涉及键的断裂则不在决速步骤中.由4位取代的HEH酯衍生物的氧化电位与2-硝基-2-亚硝基丙烷的还原电位可在热力学上判断该反应不是由电子转移引发的.向反应体系中加入单电子转移抑制剂对二硝基苯,反应未受到明显抑制,进一步证明了上述推断.据此推测,反应可能是通过NO＋直接对HEH酯上氮原子的亲电历程引发的.

英文摘要：

Hantzsch 1,4-dihydropyridine derivatives which contain 1,4-dihydropyridine structure of natural reduced nicotinamide adenine dinucleotide coenzyme and possess a high biological activity as a class of useful drugs,can be chosen as models of NAD（P）H to react with NO or its donor to mimic the oxidation of NAD（P）H by NO in vivo.Herein,4-substituted derivatives of Hantzsch 1,4-dihydropyridine were treated by 2-nitro-2-nitrosopropane to give the corresponding pyridine derivatives.Replacement of HEH by N-d-HEH and 4,4′-2d-HEH to react with 2-nitro-2-nitrosopropane gave the observed kinetic isotope effects of 1.03 and 1.78.The study of the redox potentials（cyclic voltametry） of the two reactants indicated that the oxidation of HEH by 2-nitro-2-nitrosopropane initiated by one-electron transfer was extremely unfavorable in thermodynamics.In addition,the ineffectiveness of p-dinitrobenzene on the reaction can also support it.These results indicate that the oxidation of HEH by 2-nitro-2-nitrosopropane is initiated by nitrosation to give the corresponding N-nitroso compound,which is subsequently subjected to two steps of homolytic cleavage to afford the aromatized Hantzsch pyridine.We believe that the present work will stimulate the investigations of the chemical features of C-nitroso compounds and its role in biological and medicinal chemistry.