1-(2-ethoxy-2-oxoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-one | 1006032-72-9

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: 1-(2-ethoxy-2-oxoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-one
• 英文别名: 1-ethoxycarbonylmethyl-5,5,7,7-tetramethyl-2-oxo-tetrahydroimidazo[1,5-b]oxadiazol-6-oxyl
• CAS: 1006032-72-9
• 化学式: C₁₂H₂₀N₃O₅
• 分子量: 286.308
• InChiKey: ARLYFBIJNHNUHY-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.2
• 重原子数：
  20
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  63.3
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  1-(2-ethoxy-2-oxoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-one 在 sodium azide 作用下， 以 水 、 N,N-二甲基甲酰胺 为溶剂， 反应 2.0h， 以86%的产率得到(1-oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-imidazol-4-ylamino)acetic acid ethyl ester
  参考文献：
  名称：

  Studies toward the Synthesis of 4-(2-R-ethyl)amino-2,2,5,5-tetramethyl-3-imidazoline 1-Oxyls. Nucleophilic Substitution of Bromide in the N-Alkyl Chain of the 1,2,4-Oxadiazol-2-one Precursor

  摘要：

  [GRAPHICS]A synthetic approach to access the new nitroxides of the amidine type exhibiting pH-dependent EPR spectra through substitution of a halide in the exo-N-halogenoalkyl chain of 1-(2-bromoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2-one is reported. In this approach, an oxycarbonyl moiety of the oxadiazolone heterocycle plays the role of a "protecting group" for the amidine functionality. A nucleophilic cleavage of the oxadiazolone heterocycle under mild nonbasic conditions, applicable to substrates bearing substituents vulnerable to attack by strong basic nucleophiles, is elaborated. The approach allows for the new amidine nitroxides bearing various functional groups (e.g., such as CN, N-3, NH2, COOEt) to be synthesized. A series of nitroxides obtained through the Staudinger/intermolecular aza-Wittig reaction of the azido derivative is also described. The nitroxides synthesized here were found to have pfl-dependent two-component EPR spectra indicative of a slow, on the EPR time scale, R-center dot reversible arrow (RH+)-H-center dot chemical exchange, and pK(a) values ranging from 2.8 to 12.5 units. The guanidine derivatives synthesized in this work show the highest pK(a) values (pK(a) = 10.2 and 12.5, respectively) ever reported for the nitroxide pH-probes of a "basic type".

  DOI：

  10.1021/jo701803a
• 作为产物：
  描述：

  2,2,5,5-tetramethyl-3-imidazoline-3-oxide-1-oxyl 、 异氰酰乙酸乙酯 以 二氯甲烷 为溶剂， 以85%的产率得到1-(2-ethoxy-2-oxoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-one
  参考文献：
  名称：

  Studies toward the Synthesis of 4-(2-R-ethyl)amino-2,2,5,5-tetramethyl-3-imidazoline 1-Oxyls. Nucleophilic Substitution of Bromide in the N-Alkyl Chain of the 1,2,4-Oxadiazol-2-one Precursor

  摘要：

  [GRAPHICS]A synthetic approach to access the new nitroxides of the amidine type exhibiting pH-dependent EPR spectra through substitution of a halide in the exo-N-halogenoalkyl chain of 1-(2-bromoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2-one is reported. In this approach, an oxycarbonyl moiety of the oxadiazolone heterocycle plays the role of a "protecting group" for the amidine functionality. A nucleophilic cleavage of the oxadiazolone heterocycle under mild nonbasic conditions, applicable to substrates bearing substituents vulnerable to attack by strong basic nucleophiles, is elaborated. The approach allows for the new amidine nitroxides bearing various functional groups (e.g., such as CN, N-3, NH2, COOEt) to be synthesized. A series of nitroxides obtained through the Staudinger/intermolecular aza-Wittig reaction of the azido derivative is also described. The nitroxides synthesized here were found to have pfl-dependent two-component EPR spectra indicative of a slow, on the EPR time scale, R-center dot reversible arrow (RH+)-H-center dot chemical exchange, and pK(a) values ranging from 2.8 to 12.5 units. The guanidine derivatives synthesized in this work show the highest pK(a) values (pK(a) = 10.2 and 12.5, respectively) ever reported for the nitroxide pH-probes of a "basic type".

  DOI：

  10.1021/jo701803a

文献信息

• Studies toward the Synthesis of 4-(2-R-ethyl)amino-2,2,5,5-tetramethyl-3-imidazoline 1-Oxyls. Nucleophilic Substitution of Bromide in the <i>N</i>-Alkyl Chain of the 1,2,4-Oxadiazol-2-one Precursor
  作者：Julya F. Polienko、Thomas Schanding、Yury V. Gatilov、Igor A. Grigor'ev、Maxim A. Voinov

  DOI：10.1021/jo701803a

  日期：2008.1.1

  [GRAPHICS]A synthetic approach to access the new nitroxides of the amidine type exhibiting pH-dependent EPR spectra through substitution of a halide in the exo-N-halogenoalkyl chain of 1-(2-bromoethyl)-6-oxyl-5,5,7,7-tetramethyltetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2-one is reported. In this approach, an oxycarbonyl moiety of the oxadiazolone heterocycle plays the role of a "protecting group" for the amidine functionality. A nucleophilic cleavage of the oxadiazolone heterocycle under mild nonbasic conditions, applicable to substrates bearing substituents vulnerable to attack by strong basic nucleophiles, is elaborated. The approach allows for the new amidine nitroxides bearing various functional groups (e.g., such as CN, N-3, NH2, COOEt) to be synthesized. A series of nitroxides obtained through the Staudinger/intermolecular aza-Wittig reaction of the azido derivative is also described. The nitroxides synthesized here were found to have pfl-dependent two-component EPR spectra indicative of a slow, on the EPR time scale, R-center dot reversible arrow (RH+)-H-center dot chemical exchange, and pK(a) values ranging from 2.8 to 12.5 units. The guanidine derivatives synthesized in this work show the highest pK(a) values (pK(a) = 10.2 and 12.5, respectively) ever reported for the nitroxide pH-probes of a "basic type".
• Synthesis of N'-substituted amidines through the cleavage an oxadiazolone heterocycle by weakly basic nucleophiles. Effect of the nature of the nucleophile and of the nucleophile/substrate molar ratio
  作者：Yu. F. Polienko、I. A. Grigor’yev、M. A. Voinov

  DOI：10.1007/s10593-009-0226-6

  日期：2009.1

  The reaction of 1-ethoxycarbonylmethyl-5,5,7,7-tetramethyl-2-oxo-tetrahydroimidazo[1,5-b]oxadiazol-6-oxyl with the weakly basic nucleophiles NaN3, NaCN, KF, KBr, KCl and NaNO2 has been studied. It was shown for the first time that, as in the case of NaOH and MeONa, the reaction occurs with opening of the oxadiazolone ring to form exo-N-substituted amidines. It was shown that the weakly basic nucleophiles readily react with substrates which contain a substituent sensitive to attack by such nucleophiles as NaOH or MeONa. The effect of the nature of the nucleophiles on the reaction course for opening of the oxadiazolone ring was also studied. It was found that the reactivity of the nucleophiles in DMSO changes in the series F- > CN- > N (3) (-) > NO (2) (-) > Cl- > Br- and qualitatively correlates with their basicities in this solvent. Examination of the effect of the ratio of the reagents on the degree of conversion of the starting oxadiazolone has shown that a quantity of nucleophiles less than one equivalent also allowed the cleavage reaction of the oxadiazolone heterocycle to go to completion through just increasing the reaction time. The experimental data obtained lends support to the proposed reaction scheme.