Ethanol → 3-Bromo-5-(trifluoromethoxy)benzoic acid

HRID 2216769Notes

Reaction equation

HRID 2216769 reaction equation
N[C:2]1[C:10]([O:11][C:12]([F:15])([F:14])[F:13])=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[Br:16].C(O)C.S(=O)(=O)(O)O.N([O-])=O.[Na+]>O>[Br:16][C:3]1[CH:4]=[C:5]([CH:9]=[C:10]([O:11][C:12]([F:13])([F:14])[F:15])[CH:2]=1)[C:6]([OH:8])=[O:7]

Participants

6

Reactant 4

HCID 702EthanolHCID 1118Sulfuric AcidHCID 219424074-Amino-3-bromo-5-(trifluoromethoxy)benzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 27828433-Bromo-5-(trifluoromethoxy)benzoic acidYield 75.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

4-Amino-3-bromo-5-trifluoromethoxybenzoic acid (1.5 g, 5 mmoles) was mixed with ethanol (15 mL) at 0° C. and then concentrated sulfuric acid (2.26 g, 10.2 mmoles) wad added. The sodium nitrite (0.38 g, 5.5 mmoles) water solution (1.2 mL) was added dropwise at 0° C. for 1 hour. After the reaction mixture was warmed to room temperature and then heated to reflux for 45 minutes, water was added. The mixture was extracted with dichloromethane. The dichloromethane layer was dried and concentrated. The residue was dissolved in 1M sodium hydroxide and extracted with ether. The aqueous solution was acidified with 2M HCl to pH=2 to give 3-bromo-5-trifluoromethoxybenzoic acid (1.08 g, 75.5%).

Workup

  1. temperatureheated
  2. temperatureto reflux for 45 minutes
  3. extractionThe mixture was extracted with dichloromethane
  4. dry with materialThe dichloromethane layer was dried
  5. concentrationconcentrated
  6. dissolutionThe residue was dissolved in 1M sodium hydroxide
  7. extractionextracted with ether

Sources & evidence

ORD record
ord-829b86b4d17541e18a755fc5ffd0b3d4
Source dataset
uspto-grants-2006_09
Patent number
US07112595B2

Reaction notes

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