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 339950Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 339950
[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]

Komponenten

6

Edukt 3

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

Produkt 1

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

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 8028TetrahydrofuranLösungsmittelHCID 8058HexaneLösungsmittel

Versuchsvorschrift

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)+.

Aufarbeitung

  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

Quellen und Nachweise

ORD-Eintrag
ord-dad64f9723df463293755f44e4811e8c
Quelldatensatz
uspto-grants-2014_11
Patentnummer
US08895571B2

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