4-bromo-1H-pyrazole; hydrobromide | 35798-67-5

• 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: 4-bromo-1H-pyrazole; hydrobromide
• 英文别名: 4-Brom-1H-pyrazol; Hydrobromid
• CAS: 35798-67-5
• 化学式: BrH*C₃H₃BrN₂
• 分子量: 227.886
• InChiKey: DGIUZUJYZGQTEA-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.75
• 重原子数：
  7.0
• 可旋转键数：
  0.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  28.68
• 氢给体数：
  1.0
• 氢受体数：
  1.0

反应信息

• 作为产物：
  描述：

  alkaline earth salt of/the/ methylsulfuric acid 在 溴 作用下， 生成 4-bromo-1H-pyrazole; hydrobromide
  参考文献：
  名称：

  Buchner, Chemische Berichte, 1889, vol. 22, p. 2166

  摘要：

  DOI：

文献信息

• Functionalized Pyrazoles as Agents in C–C Cross-Coupling Reactions
  作者：Marijana Pejic、Sebastian Popp、Michael Bolte、Matthias Wagner、Hans-Wolfram Lerner

  DOI：10.5560/znb.2014-3224

  日期：2014.1.1

  The 1-tetrahydropyranyl-(THP-)protected pyrazoles 4-R-pz(THP) (R=pinacolatoboryl=Bpin (3a(THP)), Me₃Si (4a(THP)), Me₃Sn (5a(THP)), and 4-R-3,5-Ph₂pz (R=Bpin (3b(THP)), Me₃Si (4b(THP)), Me₃Sn (5b(THP)) were obtained by the following syntheses: i) In a first step, 4-X-pz (X=Br (1a), I (2a)) and 4-X-3,5-Ph₂pz (X=Br (1b), I (2b)) were reacted with 3,4-dihydro-2Hpyran (DHP) to give the related THP-protected bromo- or iodopyrazole derivatives. ii) In a second step these THP derivatives were metalated by treatment with nBuLi or iPrMgCl. Subsequent reactions of the THP-protected metallopyrazoles 4-M-pz(THP) and 4-M-3,5-Ph₂pz(THP) (M=Li, MgBr) with Bpin(OiPr), Me₃SiCl, and Me3SnCl yielded the pyrazole derivatives 3a(THP), 3b(THP), 4a(THP), 4b(THP), 5a(THP), and 5b(THP). In contrast to the stannylated pyrazoles 5a(THP) and 5b(THP), the corresponding borylated and silylated derivatives could be easily deprotected: treatment of 3a(THP), 3b(THP), and 4a(THP) with HCl yielded the parent pyrazoles 3a, 3b and 4a. The microwave-assisted C-C cross-coupling reactions of these pyrazoles with aryl halides were examined, e. g. Suzuki reactions of 3a with p-pentylphenylbromide, p-hexylphenylbromide, and p- (2-ethylhexyl)phenylbromide. Similar reactions were also performed with 1a, 1b, 2a, and 2b and aryl-substituted pinacolatoboranes or boronic acids. Crystals of 5b(THP) suitable for X-ray diffraction were grown (monoclinic P2_1/c) and their structure determined. The crystal structures of 1a·HBr (monoclinic P2_1/n), 1b (triclinic P̄1̄), (1c)₂·HBr (monoclinic P_2/c), 1c·HBr·(Br₂)_0.5 (triclinic P̄1̄), (2a)₃·H₂SO₄ (triclinic P̄1̄), 3a (orthorhombic P2₁2₁2₁), (3a)₃·H₂O (trigonal R3c), 3b (orthorhombic Pna2₁), and 4a (monoclinic Pc) reveal interesting hydrogen bonding networks.

  1-四氢吡喃基-(THP-)保护吡唑 4-R-pz(THP) (R=pinacolatoboryl=Bpin (3a(THP)), Me3Si (4a(THP))、Me3Sn (5a(THP)) 和 4-R-3,5-Ph2pz (R=Bpin (3b(THP)), Me3Si (4b(THP)), Me3Sn (5b(THP))) 通过以下合成方法获得：i) 第一步，4-X-pz（X=Br (1a)，I (2a)）和 4-X-3,5-Ph2pz（X=Br (1b)，I (2b)）与 3,4-二氢-2H吡喃（DHP）反应，得到相关的 THP 保护的溴或碘吡唑衍生物。ii) 第二步，用 nBuLi 或 iPrMgCl 对这些 THP 衍生物进行金属化处理。受 THP 保护的金属吡唑 4-M-pz(THP) 和 4-M-3,5-Ph2pz(THP)（M=Li、MgBr）随后与 Bpin(OiPr)、Me3SiCl 和 Me3SnCl 反应，得到吡唑衍生物 3a(THP)、3b(THP)、4a(THP)、4b(THP)、5a(THP)和 5b(THP)。与锡烷化吡唑 5a(THP) 和 5b(THP)不同，相应的硼烷化和硅烷化衍生物很容易脱保护：用盐酸处理 3a(THP)、3b(THP) 和 4a(THP)，可得到母体吡唑 3a、3b 和 4a。研究了这些吡唑与芳基卤化物的微波辅助 C-C 交叉偶联反应，例如 3a 与对戊基苯溴化物、对己基苯溴化物和对 (2- 乙基己基) 苯溴化物的铃木反应。1a、1b、2a 和 2b 与芳基取代的频哪醇硼烷或硼酸也发生了类似的反应。生长出了适合 X 射线衍射的 5b(THP)晶体（单斜 P21/c），并确定了它们的结构。1a-HBr (单斜 P21/n)、1b (三斜 P̄1̄)、(1c)2-HBr (单斜 P2/c)、1c-HBr-(Br2)0.5（三棱 P̄1̄）、(2a)3-H2SO4（三棱 P̄1̄）、3a（正交 P212121）、(3a)3-H2O（三棱 R3c）、3b（正交 Pna21）和 4a（单斜 Pc）揭示了有趣的氢键网络。
• Buchner; Fritsch, Justus Liebigs Annalen der Chemie, 1893, vol. 273, p. 252
  作者：Buchner、Fritsch

  DOI：——

  日期：——