1-Pyrrolidinyloxy, 5-hydroxy-2,2,4,4-tetramethyl- | 78139-66-9

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡咯烷类
• 英文名称: 1-Pyrrolidinyloxy, 5-hydroxy-2,2,4,4-tetramethyl-
• 英文别名: 3,3,5,5-Tetramethyl-2-hydroxypyrrolidine-1-oxyl radical；M4PO-OH
• CAS: 78139-66-9
• 化学式: C₈H₁₆NO₂
• 分子量: 158.221
• InChiKey: NYKKRBMRNKLXJZ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.16
• 重原子数：
  11.0
• 可旋转键数：
  0.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  43.37
• 氢给体数：
  1.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  3,3,5,5-四甲基-1-吡咯啉 N-氧化物 在 水 、 氧气 作用下， 反应 0.08h， 以Ca. 30 μmol的产率得到1-Pyrrolidinyloxy, 5-hydroxy-2,2,4,4-tetramethyl-
  参考文献：
  名称：

  Reevaluation of Quantitative ESR Spin Trapping Analysis of Hydroxyl Radical by Applying Sonolysis of Water as a Model System

  摘要：

  使用 5,5-二甲基-1-吡咯啉 N-氧化物（DMPO）进行电子自旋共振（ESR）自旋捕获通常用于羟基自由基的定量分析。为了更好地理解这种分析方法，我们研究了 DMPO 与 3,3,5,5-四甲基-1-吡咯啉 N-氧化物（M4PO）和 5-（二苯基膦酰基）-5-甲基-1-吡咯啉 N-氧化物（DPPMPO）相比，羟自由基自旋加合物的形成和衰减动力学。在通过超声溶解水产生羟基自由基的研究中，我们发现：(1) 即使羟基自由基持续产生，DMPO-OH 的形成也是饱和的；(2) 停止超声辐照后，DMPO-OH 的浓度与时间成反比下降，这表明衰减是一个二阶反应。通过光解 H2O2 生成 DMPO-OH 的实验也得到了类似的结果。除 DMPO 外，M4PO 和 DPPMPO 也能捕获羟基自由基，但自旋捕获效率低于 DMPO。此外，M4PO-OH 和 DPPMPO-OH 的衰变速度比 DMPO-OH 快。由此，我们得出结论：DMPO 比 M4PO 和 DPPMPO 更适合用于羟自由基的定量分析，但在解释定量分析结果时必须考虑到与 DMPO-OH 的形成和衰变有关的动力学，尤其是在定量分析大量羟自由基生成时。

  DOI：

  10.1246/bcsj.20100078

文献信息

• Mechanistic Studies by Electron Paramagnetic resonance Spectroscopy on the Formation of 2-(N-Chloroimino)-5,5-dimethylpyrrolidine-1-oxyl Radical from 5,5-Dimethyl-1-pyrroline 1-Oxide and Hypochlorite-Treated Ammonia
  作者：B. M. Ratnayake Bandara、Oscar Hinojosa、Carl Bernofsky

  DOI：10.1021/jo00086a013

  日期：1994.4

  Mixtures of ammonium ion (NH4+) or ammonia (NH3), hypochlorous acid (HOCl), and 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) gave the radical 2-(N-chloroimino)-5,5-dimethylpyrrolidin-1-oxyl (1). The first step in the formation of 1 was the reaction of HOCl and NH4+ to provide ammonia chloramines: monochloramine (NH2Cl), dichloramine (NHC2), and trichloramine (NCl3). Chloramine composition and the formation of 1 were dependent on pH, the ratio of NH4+ to HOCl, and, at acidic pH, on the concentration of chloride in the medium. Conditions were chosen to isolate the individual chloramines in solution for further study. NCl3 and DMPO gave 1; however, NHCl2 and NH2Cl required additional oxidants such as HOCl or PbO2 to produce 1. Studies with N-15-labeled chloramines confirmed that NHCl2 and NH2Cl reacted with DMPO to form N-chloro intermediates that yielded 1 upon subsequent oxidation. Light had no effect on the formation of 1, and UV irradiation did not enhance the EPR signal intensity but caused rapid decay, indicating that radical intermediates of ammonia chloramines were not involved. The mechanism of formation of 1 appeared to involve temporary attachment of chloramine Cl to the nitroxide oxygen of DMPO which activated its beta-carbon for nucleophilic addition of the chloramine N. SubsequentN-chlorination and/or dehydrochlorination, depending on the reactive chloramine, would then provide 1. However, nucleophilic addition of H2O to the activated beta-carbon of DMPO was competitive because 5,5-dimethyl-2-hydroxypyrrolidine-1-oxyl (DMPO-OH) or 5,5-dimethyl-2-pyrrolidone-1-oxyl(DMPOX) radicals were sometimes observed as minor products along with 1. Analogous chloroimine radicals were not obtained from the reaction of ammonia chloramines with 3,3,4,4-tetramethyl-1-pyrroline 1-oxide (M(4)PO) and N-tert-butyl-alpha-phenylnitrone (PBN), although their 2-oxo nitroxyl derivatives and hydroxyl adducts were formed as radical products suggesting that nucleophilic addition of H2O was dominant with these nitroxides.