反応 #487553

反応方程式

sodium nitrite

hydrobromic acid

4-ethyl-3-nitroaniline

Hydrobromic acid

→

4-bromo-1-ethyl-2-nitrobenzene

溶媒

water

water

反応条件

後処理

1. 1
   workup.DISSOLUTIONdissolves
2. 2
   温度maintaining the temperature at 0-5° C
3. 3
   workup.ADDITIONOnce the addition
4. 4
   その他the 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
   温度to warm to room temperature over three hours
8. 8
   抽出The mixture is extracted with diethyl ether
9. 9
   乾燥dried over anhydrous sodium sulfate
10. 10
    ろ過filtered
11. 11
    濃縮the filtrate is concentrated in vacuo
12. 12
    その他The residue is further purified by column chromatography on silica gel
13. 13
    洗浄eluting with hexane

実験手順

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)

出典