Reaktion #487553

Reaktionsgleichung

sodium nitrite

hydrobromic acid

4-ethyl-3-nitroaniline

Hydrobromic acid

→

4-bromo-1-ethyl-2-nitrobenzene

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   Temperaturmaintaining the temperature at 0-5° C
3. 3
   workup.ADDITIONOnce the addition
4. 4
   Sonstigethe 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
   Temperaturto warm to room temperature over three hours
8. 8
   ExtraktionThe mixture is extracted with diethyl ether
9. 9
   Trocknendried over anhydrous sodium sulfate
10. 10
    Filtrationfiltered
11. 11
    Einengenthe filtrate is concentrated in vacuo
12. 12
    SonstigeThe residue is further purified by column chromatography on silica gel
13. 13
    Wascheneluting with hexane

Vorschrift

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)

Quelle