4-methoxy-5,5-dimethyl-2-(4-methoxycarbonylbutyl)-2-imidazoline 3-oxide 1-oxyl | 104868-47-5

• 分子结构分类: 有机化合物 - 有机杂环化合物
• 英文名称: 4-methoxy-5,5-dimethyl-2-(4-methoxycarbonylbutyl)-2-imidazoline 3-oxide 1-oxyl
• CAS: 104868-47-5
• 化学式: C₁₈H₂₅N₂O₅
• 分子量: 349.407
• InChiKey: RGPDSLGNQMJKHN-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.9
• 重原子数：
  25
• 可旋转键数：
  8
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.56
• 拓扑面积：
  68.5
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  甲醇 、 5,5-dimethyl-1-hydroxy-2-(spirocyclohexan-2-one 2)-4-phenyl-3-imidazoline 3-oxide 在 lead dioxide 作用下， 反应 24.0h， 生成 4-methoxy-5,5-dimethyl-2-(4-methoxycarbonylbutyl)-2-imidazoline 3-oxide 1-oxyl
  参考文献：
  名称：

  Conversion of 3-imidazoline-3-oxide nitroxyl radicals into nitronylnitroxyl radicals

  摘要：

  DOI：

  10.1007/bf00963256

文献信息

• ESR and1H NMR studies of a new class of nitroxyl, nitronylnitroxyl and iminonitroxyl radicals
  作者：V. V. Khramtsov、L. M. Weiner、A. Z. Gogolev、I. A. Grigor'ev、V. F. Starichenko、L. B. Volodarsky

  DOI：10.1002/mrc.1260240304

  日期：1986.3

  A new synthesis of nitronylnitroxyl (NNR), iminonitroxyl (INR) and nitroxyl radicals (NR) is suggested, involving oxidation of 4H-imidazol di-N-oxides with O2 or PbO2 in the presence of nucleophilic reagents. This method allowed the preparation of radicals which could not be synthesized by known procedures. These radicals were studied by ESR and 1H NMR spectroscopy. The hyperfine interaction constants of the NNR were measured and assigned (in some cases radicals containing 15N were used). The influence of protonation and deprotonation of functional groups (OH, NH2) in the NNR on their ESR spectra was investigated and the pK values of these radicals were measured by ESR. Differences between the ESR spectra of two isomeric INR were found, and the structures of these radicals were established by 1H NMR. Changes in spin density delocalization in 3-imidazoline 3-oxide nitroxyl radicals were studied, and the spin density was found to be ‘pushed out’ to the peripheral fragments of these radicals on increasing the number of methoxy groups in the α-position to the N—O. fragment. Hindered rotation around the σ-bond of a bulky substituent in the α-position to the N—O. fragment was detected by ESR. The activation energy of this hindered rotation was ΔE = 30±1.7 kJ mol−1.

  本研究提出了一种新的硝酰硝基（NNR）、亚硝酰硝基（INR）和硝基自由基（NR）的合成方法，包括在亲核试剂存在下用 O2 或 PbO2 氧化 4H-imidazol 二-N-氧化物。这种方法可以制备出已知程序无法合成的自由基。通过 ESR 和 1H NMR 光谱对这些自由基进行了研究。对 NNR 的超频相互作用常数进行了测量和分配（在某些情况下使用了含有 15N 的自由基）。研究了 NNR 中官能团（OH、NH2）的质子化和去质子化对其 ESR 光谱的影响，并通过 ESR 测定了这些自由基的 pK 值。 发现了两种异构体 INR 的 ESR 光谱之间的差异，并通过 1H NMR 确定了这些自由基的结构。研究了 3-imidazoline 3-oxide nitroxyl 自由基中自旋密度分散的变化，发现当 N-O. 片段 α 位置上的甲氧基数量增加时，自旋密度会被 "挤出 "到这些自由基的外围片段。ESR 检测到了 N-O 片段 α 位上的一个大块取代基围绕 σ 键的受阻旋转。这种受阻旋转的活化能为 ΔE = 30±1.7 kJ mol-1。