Reacción #170944

Ecuación de reacción

NaHCO3

1-bromo-4-fluoro-2-methyl-5-nitrobenzene

SnCl2.2H2O

→

5-bromo-2-fluoro-4-methylaniline

Rendimiento 31.9%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture was heated
2. 2
   Temperaturaat reflux for 3 h
3. 3
   OtroThe solvent was evaporated under reduced pressure
4. 4
   Otroto give a residue, which
5. 5
   FiltraciónThe solid was filtered off
6. 6
   Extracciónthe filtrate was extracted with dichloromethane (200 mL×3)
7. 7
   SecadoThe combined organics were dried over anhydrous Na2SO4
8. 8
   Otroevaporated under reduced pressure
9. 9
   OtroThe residue was purified by column chromatography (petroleum ether/EtOAc=10/1)

Procedimiento

To a stirred solution of 1-bromo-4-fluoro-2-methyl-5-nitrobenzene (18.0 g) in ethanol (300 mL) was added SnCl2.2H2O (51.8 g, 0.230 mol) at room temperature. The mixture was heated at reflux for 3 h. The solvent was evaporated under reduced pressure to give a residue, which was poured into ice water. The aqueous phase was basified with sat. NaHCO3 to pH 7. The solid was filtered off and the filtrate was extracted with dichloromethane (200 mL×3). The combined organics were dried over anhydrous Na2SO4 and evaporated under reduced pressure. The residue was purified by column chromatography (petroleum ether/EtOAc=10/1) to afford 5-bromo-2-fluoro-4-methylaniline (5.0 g, 30% yield for two steps). 1H NMR (400 MHz, CDCl3) δ 6.96 (d, J=8.8 Hz, 1H), 6.86 (d, J=11.6 Hz, 1H), 3.64 (br, 2H), 2.26 (s, 3H). MS (ESI) m/z (M+H+) 204.0.

Fuente