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

HRID 1455741

반응식

HRID 1455741 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

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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-b5e1f0b400a14ba0a5726b846efbb2de
출처 데이터셋
uspto-grants-2009_01
특허 번호
US07482350B2

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