Acetic Acid → 1H-Pyrazole-5-carboxylic acid, 1-methyl-3-propyl-, ethyl ester

HRID 354163노트

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HRID 354163 반응식
[C:1]([O:8][CH2:9][CH3:10])(=[O:7])[C:2](OCC)=O.[CH3:11][C:12](=O)[CH2:13][CH2:14][CH3:15].[Na].C(O)(=O)C.[CH3:22][NH:23][NH2:24]>C(O)C>[CH3:22][N:23]1[C:2]([C:1]([O:8][CH2:9][CH3:10])=[O:7])=[CH:11][C:12]([CH2:13][CH2:14][CH3:15])=[N:24]1

참가 물질

7

반응물 5

HCID 176Acetic AcidHCID 6061MethylhydrazineHCID 7268Diethyl OxalateHCID 78952-PentanoneHCID 5360545Sodium

생성물 1

HCID 101765321H-Pyrazole-5-carboxylic acid, 1-methyl-3-propyl-, ethyl ester수율 15.5%

시약·촉매·용매 1

HCID 702Ethanol용매

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온도
60 °C

실험 절차

A solution of diethyl oxalate (27.2 mL, 0.2 mol) in 2-pentanone (21.2 mL, 0.2 mol) was added dropwise to a solution of sodium (4.83 g, 0.21 mol) in ethanol (200 mL), and the reaction stirred at 60° C. for 5 h, then cooled in an ice-bath. The solution was neutralised using acetic acid (11.5 mL, 0.2 mol) and N-methyl hydrazine (10.6 mL, 0.2 mol) then added dropwise. The mixture was stirred for a further 4 h at room temperature and concentrated under reduced pressure. The residue was partitioned between dichloromethane (300 mL) and water (200 mL), and the phases separated. The aqueous layer was extracted with dichloromethane (3×100 mL), the combined organic solutions were dried (MgSO4) and evaporated under reduced pressure. The crude product was purified by column chromatography on silica gel, using ethyl acetate:hexane (25:75) as eluant to give ethyl 1-methyl-3-n-propyl-pyrazole-5-carboxylate (6.1 g) and the title compound (22.1 g, 56%).

후처리

  1. temperaturecooled in an ice-bath
  2. additionthen added dropwise
  3. stirringThe mixture was stirred for a further 4 h at room temperature
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was partitioned between dichloromethane (300 mL) and water (200 mL)
  6. customthe phases separated
  7. extractionThe aqueous layer was extracted with dichloromethane (3×100 mL)
  8. dry with materialthe combined organic solutions were dried (MgSO4)
  9. customevaporated under reduced pressure
  10. customThe crude product was purified by column chromatography on silica gel

출처 및 근거

ORD 기록
ord-459b05afdf3b4fb5887d1c7b77447c8f
출처 데이터셋
uspto-grants-2004_06
특허 번호
US06756373B1

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