Tributyl borate → (5-Isopropyl-1H-indazol-4-yl)boronic acid

HRID 1091921

반응식

HRID 1091921 반응식
Br[C:2]1[C:10]([CH:11]([CH3:13])[CH3:12])=[CH:9][CH:8]=[C:7]2[C:3]=1[CH:4]=[N:5][NH:6]2.[Li]C(C)(C)C.[B:19](OCCCC)([O:25]CCCC)[O:20]CCCC>CCOCC>[CH:11]([C:10]1[CH:9]=[CH:8][C:7]2[NH:6][N:5]=[CH:4][C:3]=2[C:2]=1[B:19]([OH:25])[OH:20])([CH3:13])[CH3:12]

참가 물질

5

반응물 3

HCID 12712Tributyl borateHCID 225669164-Bromo-5-isopropyl-1H-indazoleHCID 178418306HCID 178418306, 화합물

생성물 1

HCID 57358541(5-Isopropyl-1H-indazol-4-yl)boronic acid

시약·촉매·용매 1

HCID 3283Diethyl Ether용매2회

반응 조건

온도
-78 °C

실험 절차

A solution of 4-bromo-5-isopropyl-1H-indazole (1.6 g, 6.9 mmol) in Et2O (4 mL) is added slowly to a suspension of KH (1.0 g of 30% dispersion in mineral oil, 7.7 mmol) in Et2O (20 mL) at 0° C. and the mixture is stirred for 20 min. After cooling to −78° C., t-BuLi (8.9 mL of 1.7 M in Hex, 15 mmol) is added and the resulting mixture is stirred for 40 min at −78° C. To this is added B(On-Bu)3 (5.6 mL, 21 mmol) and the mixture is stirred for 24 h at room temperature. The reaction mixture is quenched with 1N H3PO4 and extracted with Et2O. The combined Et2O layers are back-extracted with 1N NaOH (3×10 mL). The combined NaOH extracts are acidified with 1N H3PO4 and extracted with EtOAc. The EtOAc extracts are washed with saturated brine, dried (MgSO4), and concentrated to yield 5-isopropyl-1H-indazole-4-boronic acid. 1H NMR (CDCl3) 7.85 (s, 1H), 7.42 (d, 1H), 7.37 (d, 1H), 3.6 (br s, 2H), 2.88 (m, 1H), 1.32 (d, 6H).

후처리

  1. stirringthe resulting mixture is stirred for 40 min at −78° C
  2. stirringthe mixture is stirred for 24 h at room temperature
  3. customThe reaction mixture is quenched with 1N H3PO4
  4. extractionextracted with Et2O
  5. extractionThe combined Et2O layers are back-extracted with 1N NaOH (3×10 mL)
  6. extractionextracted with EtOAc
  7. washThe EtOAc extracts are washed with saturated brine
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated

출처 및 근거

ORD 기록
ord-1acbba55ca0b4572a0e580d03abaa510
출처 데이터셋
uspto-grants-2012_03
특허 번호
US08129395B2

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