Reaktion #1951067

Reaktionsgleichung

4-Bromo-fluorobenzene

diethyl phosphite

triethylamine

→

4-fluorophenyl-phosphonic acid diethyl ester

Ausbeute 94.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting solution was degassed with nitrogen
2. 2
   Temperaturto cool to ambient temperature
3. 3
   WaschenThe solution was washed with saturated sodium bicarbonate (350 mL)
4. 4
   workup.DISTILLATIONThe crude product was purified by vacuum distillation (ca. 98° C., 0.6 Torr)

Vorschrift

4-Bromo-fluorobenzene (10.95 g, 62.57 mmol) was added to diethyl phosphite (8.86 mL, 68.8 mmol) at ambient temperature, followed by the addition of triethylamine (9.6 mL, 68.8 mmol). The resulting solution was degassed with nitrogen followed by the addition of tetrakis(triphenylphosphine)-palladium (3.0 g, 2.6 mmol). The resulting mixture was heated at 90° C. overnight. The reaction mixture was allowed to cool to ambient temperature and then ethyl acetate (350 mL) was added. The solution was washed with saturated sodium bicarbonate (350 mL) and then with saturated brine (2×350 mL). The crude product was purified by vacuum distillation (ca. 98° C., 0.6 Torr) to yield 8.956 g of 4-fluorophenyl-phosphonic acid diethyl ester (38.6 mmol, 94% yield) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 7.88-7.80 (m, 2H); 7.20-7.14 (m 2H); 4.22-4.04 (m, 4H); 1.36-1.32 (t, 6H); ESMS (m/z): M+1)+ found, 233.

Quelle