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

HRID 339950ノート

反応式

HRID 339950 の反応式
[CH2:1]([S:3][CH2:4][C:5]1[CH:6]=[N:7][N:8]([CH3:10])[CH:9]=1)[CH3:2].C([Li])CCC.C(O[B:20]1[O:24][C:23]([CH3:26])([CH3:25])[C:22]([CH3:28])([CH3:27])[O:21]1)(C)C>O1CCCC1.CCCCCC>[CH2:1]([S:3][CH2:4][C:5]1[CH:6]=[N:7][N:8]([CH3:10])[C:9]=1[B:20]1[O:24][C:23]([CH3:26])([CH3:25])[C:22]([CH3:28])([CH3:27])[O:21]1)[CH3:2]

参加物

6

反応物 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 119614244-[(ethylthio)methyl]-1-methyl-1H-pyrazoleHCID 178418339Butyllithium

生成物 1

HCID 866814474-[(ethylthio)methyl]-1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole収率 86%

試薬・触媒・溶媒 2

HCID 8028Tetrahydrofuran溶媒HCID 8058Hexane溶媒

実験手順

To a solution of 4-[(ethylthio)methyl]-1-methyl-1H-pyrazole (0.81 g, 5.2 mmol) in tetrahydrofuran (3.0 mL) at 0° C. was added 1.6 M n-butyllithium in hexane (6.3 mL, 10. mmol). The solution was stirred at room temperature for 1 h and then cooled down to −78° C. To the solution was added 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.06 mL, 10.1 mmol). The reaction was continued at −78° C. for 0.5 h, then warmed up to 0° C. (taking about 0.5 h). The reaction mixture was quenched with brine, adjusted to PH=6-7 with 1 N HCl aqueous solution, extracted with EtOAc (2×). The combined organic phases were washed with brine, dried over Na2SO4, and concentrated under reduced pressure to give one oil residue which was purified by combi-flash chromatography eluted with EtOAc/hexane (20-100%). The purification gave 1.2 g (86% yield) of the desired product as yellowish oil. LC-MS found: 283.1 (M+H)+.

後処理

  1. temperaturecooled down to −78° C
  2. waitThe reaction was continued at −78° C. for 0.5 h
  3. temperaturewarmed up to 0° C. (taking about 0.5 h)
  4. customThe reaction mixture was quenched with brine
  5. extractionextracted with EtOAc (2×)
  6. washThe combined organic phases were washed with brine
  7. dry with materialdried over Na2SO4
  8. concentrationconcentrated under reduced pressure
  9. customto give one oil residue which
  10. customwas purified by combi-flash chromatography
  11. washeluted with EtOAc/hexane (20-100%)
  12. customThe purification

出典と根拠

ORDレコード
ord-dad64f9723df463293755f44e4811e8c
出典データセット
uspto-grants-2014_11
特許番号
US08895571B2

反応ノート

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