Methyl iodide → Methyl 1-methyl-4-nitro-1H-pyrazole-3-carboxylate

HRID 467648ノート

反応式

HRID 467648 の反応式
[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][NH:7][N:6]=1)=[O:4].[C:13]([O-])([O-])=O.[K+].[K+].CI>CC(C)=O>[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][N:7]([CH3:13])[N:6]=1)=[O:4]

参加物

5

反応物 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 178499180HCID 178499180、化合物

生成物 1

HCID 54775322Methyl 1-methyl-4-nitro-1H-pyrazole-3-carboxylate収率 54%

試薬・触媒・溶媒 1

HCID 180Acetone溶媒

反応条件

温度
0 °C

実験手順

To a solution of 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester (3.1 g, 18.1 mmol) in dry acetone (2 ml) was added K2CO3 (5 g, 36.2 mmol) at 25° C. The reaction mixture was cooled to 0° C., and methyl iodide (2.2 ml, 36.3 mmol) was added. The temperature was again raised to 25° C., and then heated to 70° C. for 2 hrs. The solvent was removed in vacuo The residue was diluted with EtOA and washed with water and with brine, dried (Na2SO4), filtered, and concentrated. The crude product was purified by column chromatography over silica gel. Elution with 20% EtOAc/hexane) gave the undesired isomer 2-methyl-4-nitro-2H-pyrazole-3-carboxylic acid methyl ester (1 g, 30%), subsequent elution with 40% EtOAc/hexane provided the desired isomer 1-methyl-4-nitro-1H-pyrazole-3-carboxylic acid methyl ester (1.8 g, 54%).

後処理

  1. temperatureThe temperature was again raised to 25° C.
  2. temperatureheated to 70° C. for 2 hrs
  3. customThe solvent was removed in vacuo The residue
  4. additionwas diluted with EtOA
  5. washwashed with water and with brine
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe crude product was purified by column chromatography over silica gel
  10. washElution with 20% EtOAc/hexane)
  11. customgave
  12. washthe undesired isomer 2-methyl-4-nitro-2H-pyrazole-3-carboxylic acid methyl ester (1 g, 30%), subsequent elution with 40% EtOAc/hexane

出典と根拠

ORDレコード
ord-741831b6b987474b8a61431a02341d7c
出典データセット
uspto-grants-2014_01
特許番号
US08623866B2

反応ノート

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