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

HRID 1455741ノート

反応式

HRID 1455741 の反応式
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]

参加物

5

反応物 3

HCID 12712Tributyl borateHCID 225669164-Bromo-5-isopropyl-1H-indazoleHCID 178418306HCID 178418306、化合物

生成物 1

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

試薬・触媒・溶媒 1

HCID 3283Diethyl Ether溶媒2 回

反応条件

温度
-78 °C

実験手順

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).

後処理

  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

出典と根拠

ORDレコード
ord-b5e1f0b400a14ba0a5726b846efbb2de
出典データセット
uspto-grants-2009_01
特許番号
US07482350B2

反応ノート

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