Reacción #487553

Ecuación de reacción

sodium nitrite

hydrobromic acid

4-ethyl-3-nitroaniline

Hydrobromic acid

→

4-bromo-1-ethyl-2-nitrobenzene

Disolventes

water

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   Temperaturamaintaining the temperature at 0-5° C
3. 3
   workup.ADDITIONOnce the addition
4. 4
   Otrothe cooling bath is removed
5. 5
   workup.STIRRINGthe reaction mixture is stirred for one hour at room temperature
6. 6
   workup.STIRRINGThe reaction mixture is stirred
7. 7
   Temperaturato warm to room temperature over three hours
8. 8
   ExtracciónThe mixture is extracted with diethyl ether
9. 9
   Secadodried over anhydrous sodium sulfate
10. 10
    Filtraciónfiltered
11. 11
    Concentraciónthe filtrate is concentrated in vacuo
12. 12
    OtroThe residue is further purified by column chromatography on silica gel
13. 13
    Lavadoeluting with hexane

Procedimiento

Hydrobromic acid (48% wt. in water, 240 ml) is added dropwise to a suspension of 4-ethyl-3-nitroaniline (20 g, 0.12 mol) in water (80 ml), and the mixture is stirred until the solid dissolves. The mixture is cooled to −5° C. and a solution of sodium nitrite (19.8 g, 0.28 mol) in water (100 ml) is added dropwise, maintaining the temperature at 0-5° C. Once the addition is complete, the cooling bath is removed and the reaction mixture is stirred for one hour at room temperature. The mixture is added dropwise to a pre-cooled solution of cuprous bromide (22.4 g, 0.16 mol) in hydrobromic acid (48% wt. in water) at 0° C. The reaction mixture is stirred and allowed to warm to room temperature over three hours. The mixture is extracted with diethyl ether, and the organic extracts are combined, dried over anhydrous sodium sulfate, filtered and the filtrate is concentrated in vacuo. The residue is further purified by column chromatography on silica gel, eluting with hexane to give 4-bromo-1-ethyl-2-nitrobenzene (18 g)

Fuente