2,3-dihydro-1,1-dimethyl-3-oxo-5-(trifluoromethyl)-1H-pyrazolium hydroxide, inner salt | 143731-80-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 氮杂环化合物
• 英文名称: 2,3-dihydro-1,1-dimethyl-3-oxo-5-(trifluoromethyl)-1H-pyrazolium hydroxide, inner salt
• 英文别名: 1,1-Dimethyl-5-(trifluoromethyl)pyrazol-1-ium-3-olate
• CAS: 143731-80-0
• 化学式: C₆H₇F₃N₂O
• 分子量: 180.13
• InChiKey: SDGAGJRDJUNZQM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.5
• 重原子数：
  12
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  35.4
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为产物：
  描述：

  4,4,4-三氟-2-丁炔乙酯 、 偏二甲肼 以 甲醇 、 水 为溶剂， 以62.1%的产率得到2,3-dihydro-1,1-dimethyl-3-oxo-5-(trifluoromethyl)-1H-pyrazolium hydroxide, inner salt
  参考文献：
  名称：

  Cyclocondensation of alkylhydrazines and .beta.-substituted acetylenic esters: synthesis of 3-hydroxypyrazoles

  摘要：

  Addition of monosubstituted alkylhydrazines to acetylenic esters with either electron-withdrawing or sterically bulky beta-substituents afforded 1-alkyl-3-hydroxy-5-substituted-pyrazoles 1 as the major regioisomeric product. By comparison, the classical cyclocondensation of alkylhydrazines with beta-keto esters gives the regioisomeric pyrazol-5-ones 2. The reaction solvent employed in these cyclocondensations can have a profound effect on regioisomeric product ratios. Addition of methylhydrazine to 5g in methylene chloride gave regiospecific formation of pyrazolinone 2o, whereas addition in water-methanol mixtures afforded hydroxypyrazole 1o as the major product. Structural assignment of regioisomers 1 and 2 are based on C-13 NMR chemical shifts, long-range heteronuclear coupling constants, and comparisons with regiochemically known hydroxypyrazoles and/or pyrazolinones. Additions of acetylene 5b to 1,1-dimethylhydrazine afforded either acyclic enehydrazone 12 or pyrazolium betaine 13 depending on the reaction conditions.

  DOI：

  10.1021/jo00047a021

文献信息

• Cyclocondensation of alkylhydrazines and .beta.-substituted acetylenic esters: synthesis of 3-hydroxypyrazoles
  作者：Bruce C. Hamper、Mitchell L. Kurtzweil、James P. Beck

  DOI：10.1021/jo00047a021

  日期：1992.10

  Addition of monosubstituted alkylhydrazines to acetylenic esters with either electron-withdrawing or sterically bulky beta-substituents afforded 1-alkyl-3-hydroxy-5-substituted-pyrazoles 1 as the major regioisomeric product. By comparison, the classical cyclocondensation of alkylhydrazines with beta-keto esters gives the regioisomeric pyrazol-5-ones 2. The reaction solvent employed in these cyclocondensations can have a profound effect on regioisomeric product ratios. Addition of methylhydrazine to 5g in methylene chloride gave regiospecific formation of pyrazolinone 2o, whereas addition in water-methanol mixtures afforded hydroxypyrazole 1o as the major product. Structural assignment of regioisomers 1 and 2 are based on C-13 NMR chemical shifts, long-range heteronuclear coupling constants, and comparisons with regiochemically known hydroxypyrazoles and/or pyrazolinones. Additions of acetylene 5b to 1,1-dimethylhydrazine afforded either acyclic enehydrazone 12 or pyrazolium betaine 13 depending on the reaction conditions.