3,4,5-tribromo-1-vinylpyrazole | 923035-87-4

• 分子结构分类: 有机化合物 - 有机卤素化合物 - 芳基卤化物
• 英文名称: 3,4,5-tribromo-1-vinylpyrazole
• 英文别名: N-vinyltribromopyrazole；1-vinyl-3,4,5-tribromo-1H-pyrazole；3,4,5-Tribromo-1-ethenyl-1H-pyrazole；3,4,5-tribromo-1-ethenylpyrazole
• CAS: 923035-87-4
• 化学式: C₅H₃Br₃N₂
• 分子量: 330.804
• InChiKey: NTACYNDTORRSGT-UHFFFAOYSA-N

物化性质

• 沸点：
  204.7±40.0 °C(Predicted)
• 密度：
  2.42±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  3.6
• 重原子数：
  10
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  17.8
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  3,4,5-tribromo-1-vinylpyrazole 在 正丁基锂 、 六氯乙烷 作用下， 以 四氢呋喃 、 正己烷 为溶剂， 反应 2.03h， 以82%的产率得到3,4-dibromo-5-chloro-1-vinylpyrazole
  参考文献：
  名称：

  The N-vinyl group as a protection group of the preparation of 3(5)-substituted pyrazoles via bromine–lithium exchange

  摘要：

  Treatment of 3,4,5-tribromopyrazole with 1,2-dibromoethane and triethylamine gave 3,4,5-tribromo-1-vinylpyrazole, which underwent regioselective bromine-lithium exchange at the 5-position. Subsequent addition of an electrophile gave 5-substituted 3,4-dibromo-1-vinylpyrazoles. These underwent bromine-lithium or bromine-magnesium exchange predominantly at the 4-position, with the regioselectivity between the 3- and 4-positions being influenced by the nature of the metal and the 5-substituent. The 5-substituted products were de-vinylated by mild treatment with KMnO4 affording 3-substituted pyrazoles. Alternatively, the 1-vinyl group could be used in ring-closing metathesis. Thus, 5-allylthio-1-vinylpyrazole produced 5H-pyrazolo[5,1-b] [1,3]thiazine upon treatment with Grubbs' second-generation catalyst. (c) 2006 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2006.10.009
• 作为产物：
  描述：

  3,4,5-三溴吡唑 、 1,2-二溴乙烷 在 三乙胺 作用下， 以 乙腈 为溶剂， 反应 7.0h， 以78%的产率得到3,4,5-tribromo-1-vinylpyrazole
  参考文献：
  名称：

  三溴吡唑的位点选择性 Suzuki-Miyaura 反应合成芳基吡唑

  摘要：

  首次报道了 N 保护的三溴吡唑的 Suzuki-Miyaura 反应。它们与三、二或一当量的芳基硼酸反应分别得到 3,4,5-三芳基吡唑、3,5-二芳基-4-溴吡唑或 5-芳基-3,4-二溴吡唑。所有反应都以非常好的位点选择性进行。

  DOI：

  10.1055/s-0030-1258489

文献信息

• Suzuki–Miyaura reactions of N-protected tribromopyrazoles. Efficient and site-selective synthesis of 3,4,5-triaryl-pyrazoles, 3,5-diaryl-4-bromopyrazoles and 5-aryl-3,4-dibromopyrazoles
  作者：Rasheed Ahmad Khera、Asad Ali、Hummera Rafique、Munawar Hussain、Jovana Tatar、Aamer Saeed、Alexander Villinger、Peter Langer

  DOI：10.1016/j.tet.2011.05.036

  日期：2011.7

  Suzuki-Miyaura reactions of N-protected tribromopyrazoles were studied. The reactions proceed with excellent site-selectivity. The first attack occurs at position 5, while the second and third attack occur at positions 3 and 4, respectively. A variety of 3,4,5-triaryl-pyrazoles, 3,5-diaryl-4-bromopyrazoles, and 5-aryl-3,4-dibromopyrazoles were efficiently prepared. The products are not readily available by other methods. (C) 2011 Elsevier Ltd. All rights reserved.