Hydrogen Bromide → 2-Bromo-3-fluorobenzoic acid

HRID 604272

Reaction equation

HRID 604272 reaction equation
N[C:2]1[C:10]([F:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].C(#N)C.[BrH:15].N([O-])=O.[Na+]>O>[Br:15][C:2]1[C:10]([F:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 6342AcetonitrileHCID 5864082-Amino-3-fluorobenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 3026222-Bromo-3-fluorobenzoic acidYield 78%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
0 °C

Procedure

In a 1 L, three necked, round-bottomed flask fitted with a dropping funnel and a thermometer, were charged 20 g (0.13 mol) of 2-amino-3-fluoro-benzoic acid and 160 mL of acetonitrile. After cooling to 0° C., 160 mL of hydrobromic acid (47%) was added dropwise over 10 min. To the resulting solution, 10 g of NaNO2 (0.145 mol) in water (20 mL) was added dropwise over 1 hour. After addition, the reaction mixture was stirred at 0° C. for 5 min, and 21.8 g of Cu(I) Br (0.15 mol) was added portionwise over 30 min. Stirring was continued at 70° C. in an oil bath for 1 hour. After cooling to 0° C., 700 mL of H2O was added and the precipitate was filtered, washed with cold water and dried under vacuum to give an orange solid corresponding to 2-bromo-3-fluoro-benzoic acid (22 g, 78%).

Workup

  1. customIn a 1 L, three necked, round-bottomed flask fitted with a dropping funnel
  2. additionAfter addition
  3. stirringStirring
  4. waitwas continued at 70° C. in an oil bath for 1 hour
  5. temperatureAfter cooling to 0° C.
  6. filtrationthe precipitate was filtered
  7. washwashed with cold water
  8. customdried under vacuum

Sources & evidence

ORD record
ord-57eede7920b94301b129255ca0c8964a
Source dataset
uspto-grants-2011_03
Patent number
US07910585B2

Linked notes

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