2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 3-cyclopropyl-1-methyl-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 2038747ノート

反応式

HRID 2038747 の反応式
Br[C:2]1[C:3]([CH:8]2[CH2:10][CH2:9]2)=[N:4][N:5]([CH3:7])[CH:6]=1.[Li]CCCC.C(O[B:20]1[O:24][C:23]([CH3:26])([CH3:25])[C:22]([CH3:28])([CH3:27])[O:21]1)(C)C>C1COCC1>[CH:8]1([C:3]2[C:2]([B:20]3[O:24][C:23]([CH3:26])([CH3:25])[C:22]([CH3:28])([CH3:27])[O:21]3)=[CH:6][N:5]([CH3:7])[N:4]=2)[CH2:10][CH2:9]1

参加物

5

反応物 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 601364774-Bromo-3-cyclopropyl-1-methyl-1H-pyrazoleHCID 178418339Butyllithium

生成物 1

HCID 601365313-cyclopropyl-1-methyl-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole収率 48%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒2 回

実験手順

To a stirred solution of 4-bromo-3-cyclopropyl-1-methyl-1H-pyrazole (500 mg, 2.5 mmol) in THF (10 mL) was added dropwise a 2.5 M solution of n-BuLi (1.4 mL, 3.5 mmol) at −78° C., and the resulting light yellow solution was stirred for 30 min. To the mixture was added a solution of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.1 mL, 5.5 mmol) in THF (1 mL), and the mixture was warmed to room temperature over 30 min. The reaction was quenched with saturated aqueous NH4Cl solution. The mixture was extracted with EtOAc (50 mL), washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by normal phase flash chromatography on silica gel (5% MeOH—CH2Cl2, Rf=0.35) to provide 3-cyclopropyl-1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (294 mg, 48%) as a yellow oil.

後処理

  1. customThe reaction was quenched with saturated aqueous NH4Cl solution
  2. extractionThe mixture was extracted with EtOAc (50 mL)
  3. washwashed with brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by normal phase flash chromatography on silica gel (5% MeOH—CH2Cl2, Rf=0.35)

出典と根拠

ORDレコード
ord-7f71f72d1a694998acb79f8d32570318
出典データセット
uspto-grants-2013_11
特許番号
US08575360B2

反応ノート

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