Sodium hydride → 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazole

HRID 1162093

Reaktionsgleichung

Reaktionsgleichung von HRID 1162093
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[N:11][NH:12][CH:13]=2)[O:3]1.[H-].[Na+].[CH3:17][Si:18]([CH2:21][CH2:22][O:23][CH2:24]Cl)([CH3:20])[CH3:19]>CN(C=O)C.C(OCC)(=O)C>[CH3:1][C:2]1([CH3:14])[C:6]([CH3:7])([CH3:8])[O:5][B:4]([C:9]2[CH:13]=[N:12][N:11]([CH2:24][O:23][CH2:22][CH2:21][Si:18]([CH3:20])([CH3:19])[CH3:17])[CH:10]=2)[O:3]1

Komponenten

6

Edukt 3

HCID 24758Sodium hydrideHCID 27242712-Chloromethyl 2-(trimethylsilyl)ethyl etherHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Produkt 1

HCID 574776664-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazoleAusbeute 61,7 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6228DimethylformamideLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Reaktionsbedingungen

Temperatur
60 °C

Versuchsvorschrift

4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (348 mg, 1.8 mmol) was dissolved in DMF (5 mL) and sodium hydride (60% dispersion, 86 mg, 2.15 mmol) added and the mixture heated to 60° C. for 5 min. Upon cooling and stirring for an additional 15 min, trimethylsilylethoxymethyl chloride (358 mg, 2.15 mmol, 381 μL) was added dropwise over 5 min and mixture stirred for 16 h. The reaction mixture was diluted with ethyl acetate (25 mL), washed with 5% lithium chloride (5×), dried over sodium sulfate and concentrated. The residue was purified by column chromatography (40 g ISCO column eluting with hexanes and ethyl acetate; gradient 100% hexanes to 50% hexanes over 30 min at 30 mL/min) to provide the SEM-protected pyrazole (360 mg, 61%) as a colorless oil; 1H NMR (500 MHz, CDCl3) δ 7.84 (s, 1H), 7.80 (s, 1H), 5.42 (s, 2H), 3.56-3.53 (t, J=8.3 Hz, 2H), 1.31 (s, 12H), 0.91-0.87 (t, J=8.3 Hz, 2H), −0.03 (s, 9H).

Aufarbeitung

  1. temperatureUpon cooling
  2. stirringmixture stirred for 16 h
  3. washwashed with 5% lithium chloride (5×)
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated
  6. customThe residue was purified by column chromatography (40 g ISCO column eluting with hexanes and ethyl acetate; gradient 100% hexanes to 50% hexanes over 30 min at 30 mL/min)

Quellen und Nachweise

ORD-Eintrag
ord-3b221d96a45f450991d5db9a4adaf5a8
Quelldatensatz
uspto-grants-2010_10
Patentnummer
US07820670B2

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