Reaktion #79006

Reaktionsgleichung

NaOH

4-cyano-3-fluoro-bromobenzene

(1,4-dihydro-4,4-dimethyl-2-oxo-2H-3,1-benzoxazin-6-yl)boronic acid

sodium carbonate

→

title compound

Ausbeute 6.0%

6-(4-Cyano-3-fluoro-phenyl)-4,4-dimethyl-1,4-dihydrobenzo[d][1,3]-oxazin-2-one

Ausbeute 6.0%

Lösungsmittel

water

ethylene glycol dimethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto reflux for 18 hours
2. 2
   Extraktionextracted with EtOAc (3×50 mL)
3. 3
   WaschenThe combined extracts were washed with water, brine
4. 4
   Trocknendried (MgSO4)
5. 5
   Sonstigeevaporated
6. 6
   SonstigeThe residue was purified by column chromatography (SiO2, EtOAc:hexane=1:2)

Vorschrift

A solution of 4-cyano-3-fluoro-bromobenzene (0.6 g, 3.0 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.2 g) in ethylene glycol dimethyl ether (20 mL) was stirred under N2 for 20 minutes. To this mixture was then added (1,4-dihydro-4,4-dimethyl-2-oxo-2H-3,1-benzoxazin-6-yl)boronic acid (1.0 g, 4.5 mmol) and sodium carbonate (1.1 g, 10.6 mmol) in water (5 mL). The solution was brought to reflux for 18 hours and then cooled to room temperature, poured into 2N NaOH and extracted with EtOAc (3×50 mL). The combined extracts were washed with water, brine, dried (MgSO4), and evaporated. The residue was purified by column chromatography (SiO2, EtOAc:hexane=1:2) to afford the title compound (0.05 g, 6%) as an off-white solid. mp: 272-275° C.; 1H-NMR (DMSO-d6) δ 10.4 (s, 1H), 8.0 (t, 1H, J=7.7 Hz), 7.9 (dd, 1H, J=10.3, 1.3 Hz), 7.8 (dd, 1H, J=6.8, 1.4 Hz), 7.7 (m, 2H), 6.9 (d, 1H, J=8.9 Hz), 1.7 (s, 6H); MS (EI) M+ @ m/z 296.

Quelle