Acetic Anhydride → Methyl 1-acetyl-1H-indazole-5-carboxylate

HRID 22656

반응식

HRID 22656 반응식
[CH3:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[NH2:12])[C:5]([O:7][CH3:8])=[O:6].[C:13]([O-:16])(=O)[CH3:14].[K+].C(OC(=O)C)(=O)C.C1OCCOCCOCCOCCOCCOC1.CCCCCO[N:49]=O>C(Cl)(Cl)Cl>[C:13]([N:12]1[C:11]2[C:2](=[CH:3][C:4]([C:5]([O:7][CH3:8])=[O:6])=[CH:9][CH:10]=2)[CH:1]=[N:49]1)(=[O:16])[CH3:14]

참가 물질

7

반응물 5

HCID 7918Acetic AnhydrideHCID 10026Pentyl nitriteHCID 2855718-Crown-6HCID 517044Potassium AcetateHCID 2736799Methyl 4-amino-3-methylbenzoate

생성물 1

HCID 22591332Methyl 1-acetyl-1H-indazole-5-carboxylate수율 47.4%

시약·촉매·용매 1

HCID 6212Chloroform용매

실험 절차

To a stirred mixture of methyl 3-methyl-4-aminobenzoate (5.0 g, 30.0 mmol) and potassium acetate (2.94 g, 30.0 mmol) in chloroform (50 mL) is added acetic anhydride (5.66 mL, 60.0 mmol). The mixture is stirred for 30 min at rt, followed by the addition of 18-crown-6 (1.58 g, 6.0 mmol) and n-amyl nitrite (7.78 g, 66.0 mmol). The mixture is heated to reflux for 16 h, followed by cooling to rt. The mixture is washed sequentially with aqueous sodium bicarbonate solution (2×), water and brine. The organic layer is dried over MgSO4, filtered and concentrated in vacuo. The crude product is purified by flash chromatography on silica gel. Elution with hexanes-EtOAc (80:20) gives 3.1 g (47%) of methyl 1-acetyl-1H-indazole-5-carboxylate as a yellow solid: 1H NMR (400 MHz, CDCl3) δ 8.52-8.50, 8.3, 8.2, 4.0, 2.8.

후처리

  1. temperatureThe mixture is heated
  2. temperatureto reflux for 16 h
  3. temperatureby cooling to rt
  4. washThe mixture is washed sequentially with aqueous sodium bicarbonate solution (2×), water and brine
  5. dry with materialThe organic layer is dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe crude product is purified by flash chromatography on silica gel
  9. washElution with hexanes-EtOAc (80:20)

출처 및 근거

ORD 기록
ord-6062662749034ec397236ef61309513e
출처 데이터셋
uspto-grants-2005_02
특허 번호
US06849620B2

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