Hexane → 3-methyl-1-(oxan-2-yl)-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 73785Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 73785
[Li]CCCC.CCCCCC.[CH3:12][C:13]1[CH:17]=[CH:16][N:15]([CH:18]2[CH2:23][CH2:22][CH2:21][CH2:20][O:19]2)[N:14]=1.CO[B:26]1[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]1>C1COCC1>[CH3:12][C:13]1[CH:17]=[C:16]([B:26]2[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]2)[N:15]([CH:18]2[CH2:23][CH2:22][CH2:21][CH2:20][O:19]2)[N:14]=1

Komponenten

6

Edukt 4

HCID 8058Hexane2×HCID 109757592-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 867026233-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazoleHCID 178418339Butyllithium

Produkt 1

HCID 717576623-methyl-1-(oxan-2-yl)-5-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A mixture of 3-methylpyrazole (3.0 g, 35.4 mmol), 3,4-dihydro-2H-pyrane (4.97 mL, 53.2 mmol) and TFA (0.02 mL, 0.260 mmol) was stirred at 85° C. for 6 h under an argon atmosphere. The RM was cooled to RT and NaH 60% in mineral oil (0.061 g, 1.524 mmol) was and the RM was stirred for 10 min. The RM was purified by bulb-to-bulb distillation to give 3-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (b.p. 150-170° C./12 mbar). A solution of n-BuLi in n-hexane (3.38 mL of 1.6 M, 5.41 mmol) was added dropwise over 10 min to a solution of 3-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (1.0 g, 5.41 mmol) in THF (12 mL) at −70° C. under a nitrogen atmosphere and The RM was stirred for 10 min and then treated dropwise with 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.898 g, 5.69 mmol) and stirred at −70° C. for 1 h. The RM was allowed to warm to RT, treated with n-hexane and the product was filtered, dissolved in water (10 mL) and acidified to pH 6 with aqueous citric acid (10%). The water was evaporated off under reduced pressure and the aqueous residue extracted with EtOAc, dried over Na2SO4 and the solvent was evaporated off under reduced pressure to give the title product as a yellow resin. UPLC-MS (Condition 3) tR=0.56 min, m/z=211.2 [M+H]+.

Aufarbeitung

  1. stirringstirred at −70° C. for 1 h
  2. filtrationthe product was filtered
  3. dissolutiondissolved in water (10 mL)
  4. customThe water was evaporated off under reduced pressure
  5. extractionthe aqueous residue extracted with EtOAc
  6. dry with materialdried over Na2SO4
  7. customthe solvent was evaporated off under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-b4214cd084f047c2a7a0e25eff1222b9
Quelldatensatz
uspto-grants-2014_09
Patentnummer
US08829195B2

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