Reaktion #61683

Reaktionsgleichung

nitric acid

1,3-dibromo-5-fluoro-2-methoxybenzene

→

1,3-Dibromo-5-fluoro-2-methoxy-4-nitrobenzene

Ausbeute 95.0%

Lösungsmittel

H2SO4

H2SO4

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintaining the temperature between 0 and 5° C
2. 2
   Sonstigequenched into ice (2.2 kg)
3. 3
   Extraktionextracted with dichloromethane (3×2 L)
4. 4
   WaschenThe combined dichloromethane extracts were washed with saturated aqueous NaHCO3 solution (2×2 L)
5. 5
   Trocknendried over Na2SO4
6. 6
   Filtrationfiltered
7. 7
   Waschenthe filter cake washed with DCM (3×400 mL)
8. 8
   EinengenThe filtrate was concentrated in vacuo at 40° C.

Vorschrift

To a stirred solution of c.H2SO4 (740 mL) at 0 to 5° C. was added 1,3-dibromo-5-fluoro-2-methoxybenzene (223.3 g, 0.786 mol). A solution of fuming nitric acid (90%, 38 mL, 0.815 mol) in c.H2SO4 (740 mL) was added dropwise, maintaining the temperature between 0 and 5° C. The reaction mixture was stirred at 3 to 5° C. for 2 hours, quenched into ice (2.2 kg) and extracted with dichloromethane (3×2 L). The combined dichloromethane extracts were washed with saturated aqueous NaHCO3 solution (2×2 L), dried over Na2SO4, filtered and the filter cake washed with DCM (3×400 mL). The filtrate was concentrated in vacuo at 40° C. to give 1,3-Dibromo-5-fluoro-2-methoxy-4-nitrobenzene as a pale orange crystalline solid (244.9 g, 95%).

Quelle