Реакция #487553

Уравнение реакции

sodium nitrite

hydrobromic acid

4-ethyl-3-nitroaniline

Hydrobromic acid

→

4-bromo-1-ethyl-2-nitrobenzene

Растворители

water

water

Условия реакции

Обработка

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   Температураmaintaining the temperature at 0-5° C
3. 3
   workup.ADDITIONOnce the addition
4. 4
   Другоеthe 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
   Температураto warm to room temperature over three hours
8. 8
   ЭкстракцияThe mixture is extracted with diethyl ether
9. 9
   Сушкаdried over anhydrous sodium sulfate
10. 10
    Фильтрацияfiltered
11. 11
    Концентрированиеthe filtrate is concentrated in vacuo
12. 12
    ДругоеThe residue is further purified by column chromatography on silica gel
13. 13
    Промывкаeluting with hexane

Методика

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)

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