Hydrogen Bromide → 5-Bromo-2-(carboxymethyl)benzoic acid

HRID 1680498Notes

Reaction equation

HRID 1680498 reaction equation
[C:1]([C:4]1[CH:9]=[C:8]([N+]([O-])=O)[CH:7]=[CH:6][C:5]=1[CH2:13][C:14]([OH:16])=[O:15])([OH:3])=[O:2].N([O-])=O.[Na+].[BrH:21]>[Pd].O>[Br:21][C:8]1[CH:7]=[CH:6][C:5]([CH2:13][C:14]([OH:16])=[O:15])=[C:4]([C:1]([OH:3])=[O:2])[CH:9]=1

Participants

6

Reactant 3

HCID 260Hydrogen BromideHCID 123034522-(Carboxymethyl)-5-nitrobenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 106349875-Bromo-2-(carboxymethyl)benzoic acid

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 962WaterSolvent2×

Procedure

A mixture of 2-carboxy-4-nitrophenylacetic acid (described by H. E. Ungnade et al., J. Org. Chem., 10, 533 (1945), 50 g, 0.22 mol) and 5% palladium on carbon (5 g) is rapidly stirred under an atmosphere of hydrogen until the nitro group is reduced. Water (300 ml) is added and the mixture is warmed to dissolve the precipitate. The mixture is filtered through diatomaceous earth. The filtrate is evaporated and 375 ml of 2 N hydrobromic acid is added. The resulting solution is cooled in an ice-bath to 0°-5° C. Sodium nitrite (15.2 g, 0.22 mol) in 50 ml of water is added while stirring. The latter solution is added slowly to a cold (0°-5° C.) stirring freshly prepared solution of cuprous bromide (150 g, 0.105 mol) in 230 ml of 49% hydrobromic acid. The reaction is stirred at room temperature for 2 hr and the precipitate is collected by filtration. The precipitate is washed with water and dried to obtain 4-bromo-2-carboxyphenylacetic acid (53 g), mp 210°-213° C.

Workup

  1. temperaturethe mixture is warmed
  2. dissolutionto dissolve the precipitate
  3. filtrationThe mixture is filtered through diatomaceous earth
  4. customThe filtrate is evaporated
  5. addition375 ml of 2 N hydrobromic acid is added
  6. temperatureThe resulting solution is cooled in an ice-bath to 0°-5° C
  7. stirringwhile stirring
  8. additionThe latter solution is added slowly to a cold (0°-5° C.)
  9. stirringThe reaction is stirred at room temperature for 2 hr
  10. filtrationthe precipitate is collected by filtration
  11. washThe precipitate is washed with water
  12. customdried

Sources & evidence

ORD record
ord-9b53afa92c084fa0b27f4555cbad11f3
Source dataset
uspto-grants-1981_06
Patent number
US04273773

Reaction notes

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