Hydrogen Bromide → 4-Bromo-1-ethyl-2-nitrobenzene

HRID 661780Notes

Reaction equation

HRID 661780 reaction equation
[CH2:1]([C:3]1[CH:9]=[CH:8][C:6](N)=[CH:5][C:4]=1[N+:10]([O-:12])=[O:11])[CH3:2].N([O-])=O.[Na+].[BrH:17]>O>[Br:17][C:6]1[CH:8]=[CH:9][C:3]([CH2:1][CH3:2])=[C:4]([N+:10]([O-:12])=[O:11])[CH:5]=1

Participants

5

Reactant 3

HCID 260Hydrogen Bromide2×HCID 227086804-Ethyl-3-nitroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 75669964-Bromo-1-ethyl-2-nitrobenzene

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
-5 °C

Procedure

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 stirred until the solid is dissolved. 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 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)

Workup

  1. dissolutionis dissolved
  2. temperaturemaintaining the temperature at 0-5° C
  3. additionOnce the addition
  4. customthe cooling bath is removed
  5. stirringthe reaction mixture is stirred for one hour at room temperature
  6. stirringThe reaction mixture is stirred
  7. temperatureto warm to room temperature over three hours
  8. extractionThe mixture is extracted with diethyl ether
  9. dry with materialdried over anhydrous sodium sulfate
  10. filtrationfiltered
  11. concentrationthe filtrate concentrated in vacuo
  12. customThe residue is further purified by column chromatography on silica gel
  13. washeluting with hexane

Sources & evidence

ORD record
ord-08e6dd23a5a24fbab2cdd683a8887902
Source dataset
uspto-grants-2011_12
Patent number
US08084649B2

Reaction notes

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