Reacción #511542

Ecuación de reacción

tert-butyllithium

HCl

vinyl boronic acid

Compound 5b

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

→

11

Rendimiento 30.0%

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

Rendimiento 30.0%

Disolventes

pentane

Water

THF

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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.

Fuente