3,4-dibromo-2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole-1-oxide | 438193-70-5

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: 3,4-dibromo-2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole-1-oxide
• 英文别名: 4,5-Dibromo-3-(4-methoxyphenyl)-1-[(4-methoxyphenyl)methyl]-2-oxidopyrazol-2-ium
• CAS: 438193-70-5
• 化学式: C₁₈H₁₆Br₂N₂O₃
• 分子量: 468.145
• InChiKey: GTXHYLXOWXIFEK-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.4
• 重原子数：
  25
• 可旋转键数：
  5
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.17
• 拓扑面积：
  48.8
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  3,4-dibromo-2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole-1-oxide 在 四(三苯基膦)钯 potassium phosphate 、 三异丙基硅烷 、 异丙基氯化镁 、 三氟乙酸 作用下， 以 四氢呋喃 、 1,4-二氧六环 、 二氯甲烷 、 水 为溶剂， 反应 40.0h， 生成 4-(4-fluorophenyl)-5-(4-methoxyphenyl)-3-(4-methylphenyl) 1-hydroxypyrazole
  参考文献：
  名称：

  Sequential Functionalization of Pyrazole 1-Oxides via Regioselective Metalation:  Synthesis of 3,4,5-Trisubstituted 1-Hydroxypyrazoles

  摘要：

  A range of 3,5-diarylated and 3,4,5-triarylated 2-(4-methoxybenzyl)pyrazole I-oxides have been prepared by regioselective deprotonation at C-5 or bromine-magnesium exchange at C-3 or C-4 followed by transmetalation with ZnCl2 and palladium(0)-catalyzed cross-coupling. Furthermore, the metalated pyrazole 1-oxides could be trapped with electrophiles. The sequential metalation/functionalization of the pyrazole I-oxides may follow the order C-5, C-3, C-4, or alternatively the order C-3, C-5, C-4. The 4-methoxybenzyl group of the functionalized 2-(4-methoxybenzyl)pyrazole 1-oxides could be removed by treatment with TFA and i-Pr3SiH in CH2Cl2, providing the corresponding functionalized 1-hydroxypyrazoles.

  DOI：

  10.1021/jo015997i
• 作为产物：
  描述：

  2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole 1-oxide 在 N-溴代丁二酰亚胺(NBS) 作用下， 以 乙腈 为溶剂， 反应 4.0h， 以98%的产率得到3,4-dibromo-2-(4-methoxybenzyl)-5-(4-methoxyphenyl)pyrazole-1-oxide
  参考文献：
  名称：

  Sequential Functionalization of Pyrazole 1-Oxides via Regioselective Metalation:  Synthesis of 3,4,5-Trisubstituted 1-Hydroxypyrazoles

  摘要：

  A range of 3,5-diarylated and 3,4,5-triarylated 2-(4-methoxybenzyl)pyrazole I-oxides have been prepared by regioselective deprotonation at C-5 or bromine-magnesium exchange at C-3 or C-4 followed by transmetalation with ZnCl2 and palladium(0)-catalyzed cross-coupling. Furthermore, the metalated pyrazole 1-oxides could be trapped with electrophiles. The sequential metalation/functionalization of the pyrazole I-oxides may follow the order C-5, C-3, C-4, or alternatively the order C-3, C-5, C-4. The 4-methoxybenzyl group of the functionalized 2-(4-methoxybenzyl)pyrazole 1-oxides could be removed by treatment with TFA and i-Pr3SiH in CH2Cl2, providing the corresponding functionalized 1-hydroxypyrazoles.

  DOI：

  10.1021/jo015997i