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

HRID 467648노트

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HRID 467648 반응식
[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]

참가 물질

5

반응물 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 178499180HCID 178499180, 화합물

생성물 1

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

시약·촉매·용매 1

HCID 180Acetone용매

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온도
0 °C

실험 절차

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%).

후처리

  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

출처 및 근거

ORD 기록
ord-741831b6b987474b8a61431a02341d7c
출처 데이터셋
uspto-grants-2014_01
특허 번호
US08623866B2

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