Hydrogen Bromide → 2,3-Dibromo-5-methylbenzoic acid

HRID 490219

Reaction equation

HRID 490219 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]([CH3:11])[CH:8]=[C:4]([C:5]([OH:7])=[O:6])[C:3]=1N.N([O-])=O.[Na+].N#N.[BrH:19]>C(O)(=O)C.O.[Cu]Br>[Br:19][C:3]1[C:2]([Br:1])=[CH:10][C:9]([CH3:11])=[CH:8][C:4]=1[C:5]([OH:7])=[O:6]

Participants

8

Reactant 4

HCID 260Hydrogen Bromide2×HCID 947NitrogenHCID 27744002-Amino-3-bromo-5-methylbenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 218526502,3-Dibromo-5-methylbenzoic acid

Reagents, catalysts & solvents 3

HCID 24593copper(I) bromideCatalystHCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

To a solution of 3-bromo-5-methylanthranilic acid (2.3 g, 10 mmol) in acetic acid (12 mL) at 0° C. was added 18% hydrobromic acid (30 mL, 30 mmol) followed by drop wise addition of a solution of sodium nitrite (690 mg, 10 mmol) in water (5 mL). After 10 min, this solution was added to a mixture of copper (I) bromide (2.15 g, 15 mmol) in 48% hydrobromic acid (7 mL) at 0° C. The mixture was allowed to warm to ambient temperature (15 minutes) and then refluxed at 50° C. until evolution of N2 was completed. The mixture was then extracted with ethyl acetate, washed with water, brine, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to provide 2.8 g of crude of the title compound. 1H NMR (300 MHz, DMSO-d6) δ 2.27 (s, 3H), 7.43 (s, 1H), 7.72 (s, 1H), 13.60 (br s, 1H); MS (DCI/NH3) m/e 310 (M+NH4)+.

Workup

  1. extractionThe mixture was then extracted with ethyl acetate
  2. washwashed with water, brine
  3. dry with materialdried with anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-7fcdbe3b791a49d199096055ef257fa4
Source dataset
uspto-grants-2009_05
Patent number
US07528134B2

Linked notes

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