Reaktion #511542

Reaktionsgleichung

tert-butyllithium

HCl

vinyl boronic acid

Compound 5b

2-Bromo-5-fluoro-[1-(methoxymethoxy)methyl]benzene

→

11

Ausbeute 30.0%

1,3-Dihydro-5-fluoro-1-vinyl-2,1-benzoxaborole

Ausbeute 30.0%

Lösungsmittel

pentane

Water

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture was stirred at −78° C. for 1 h
2. 2
   Temperaturwas warmed up to room temperature
3. 3
   workup.STIRRINGstirred overnight
4. 4
   workup.STIRRINGwas stirred at room temperature for 4 h
5. 5
   SonstigeTHF was removed under reduced pressure
6. 6
   ExtraktionThe residue was extracted with ethyl ether
7. 7
   Waschenwashed with brine
8. 8
   Trocknendried over magnesium sulfate
9. 9
   Einengenconcentrated under reduced pressure
10. 10
    SonstigeThe crude product was purified by flash column chromatography (9:1 hexane/ethyl acetate)

Vorschrift

Compound 5b (2.0 g, 8.0 mmol) in THF (30 mL) was cooled to −78° C. and tert-butyllithium (9.9 mL, 16.8 mmol) as 1.7 M solution in pentane was added slowly. After stirring at −78° C. for 30 min, dibutyl ester of vinyl boronic acid was added dropwise. The mixture was stirred at −78° C. for 1 h, then was warmed up to room temperature and stirred overnight. Concentrated HCl (4 mL) was added and was stirred at room temperature for 4 h. Water (10 mL) was added and THF was removed under reduced pressure. The residue was extracted with ethyl ether, washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The crude product was purified by flash column chromatography (9:1 hexane/ethyl acetate) to give 11 (383 mg, 30%) as a yellowish oil; 1H NMR (300 MHz, DMSO-d6) δ (ppm) 5.27 (s, 2H), 6.25 (t, J=8.5 Hz, 1H), 6.50 (d, J=9.4 Hz, 2H), 7.06-7.15 (m, 2H), 7.89 (dd, J=5.6, 7.9 Hz, 1H); ESI-MS m/z (M+H)+; HPLC purity: 98.7%; Anal. (C9H8BFO 0.1H2O)C, H.

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