Hydrogen Bromide → 3-Bromo-5-nitrobenzoic acid

HRID 852519Notes

Reaction equation

HRID 852519 reaction equation
N[C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([N+:11]([O-:13])=[O:12])[CH:10]=1)[C:5]([OH:7])=[O:6].N([O-])=O.[Na+].[BrH:18]>O>[Br:18][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([N+:11]([O-:13])=[O:12])[CH:10]=1)[C:5]([OH:7])=[O:6]

Participants

5

Reactant 3

HCID 260Hydrogen Bromide2×HCID 2393423-Amino-5-nitrobenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 2393363-Bromo-5-nitrobenzoic acidYield 88%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of 3-amino-5-nitro-benzoic acid (17.6 g, 96.6 mmol, 1 equiv) in 48% aqueous HBr solution (180 ml) at 0° C. was added portionwise NaNO2 (8.67 g, 126 mmol, 1.3 equiv) over 20 min. The temperature was kept below 8° C. during this addition. The resulting mixture was then added to a suspension of CuBr (9.7 g, 67.6 mmol, 0.7 equiv) in 48% aqueous HBr solution (50 ml) at 65° C. over 40 min. The temperature was kept above 60° C. during the addition. The resulting mixture was stirred at 70° C. for 45 min, cooled to room temperature and diluted with 1 L of water. The aqueous phase was extracted three times with Et2O. The combined organic layers were washed twice with H2O, dried over MgSO4 and concentrated in vacuo to give 3-bromo-5-nitro-benzoic acid (D5) (21 g, 88%) as a brown solid. [M−H]−=245.7, RT=2.82 min

Workup

  1. additionThe temperature was kept below 8° C. during this addition
  2. additionThe temperature was kept above 60° C. during the addition
  3. temperaturecooled to room temperature
  4. extractionThe aqueous phase was extracted three times with Et2O
  5. washThe combined organic layers were washed twice with H2O
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-a20b1c9e528b4441ae56eaf890e96b9d
Source dataset
uspto-grants-2007_08
Patent number
US07253198B2

Reaction notes

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