Hydrochloric Acid → 2-Bromopyridine-3-carboxylic acid

HRID 2230775Notes

Reaction equation

HRID 2230775 reaction equation
[Mn]([O-])(=O)(=O)=[O:2].[K+].[Br:7][C:8]1[C:13]([CH3:14])=[CH:12][CH:11]=[CH:10][N:9]=1.[OH-:15].[Na+].Cl>O>[Br:7][C:8]1[N:9]=[CH:10][CH:11]=[CH:12][C:13]=1[C:14]([OH:2])=[O:15]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 2208322-Bromo-3-methylpyridineHCID 516875Potassium Permanganate

Product 1

HCID 2332622-Bromopyridine-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Potassium permanganate (18.4 g, 116 mmol) was dissolved in water (400 mL) and added to 2-bromo-3-methylpyridine (10.0 g, 58 mmol) and refluxed for 16 hours. After cooling to room temperature, the slurry was filtered through a celite plug and rinsed with water and chloroform. The entire filtrate was transferred to a separatory funnel and the layers were separated. The aqueous layer was extracted again with CHCl3 and acidified with 6N HCl to pH 1. A white solid was obtained on standing (2.08 g of product). The pH of the remaining aqueous was adjusted to pH 4 with 2M NaOH and 2M HCl, then concentrated to <100 mL. A white precipitate was filtered. The pH was adjusted to 4 and the mixture filtered again, combining the isolated solids for a total of 3.88 g of product. The filtrate was concentrated again to <100 mL and adjusted to pH 1.5 and an additional quanitity of white solid was obtained (1.80 g), for a combined yield of 3 crops, (8.76 g, 66%). 1H NMR (DMSO-d6): δ13.76 (bs, 1H), 8.46 (m, 1H), 8.09 (dd, 1H, J=7.7, J′=2.2), 7.51 (m, 1H).

Workup

  1. temperaturerefluxed for 16 hours
  2. filtrationthe slurry was filtered through a celite plug
  3. washrinsed with water and chloroform
  4. customThe entire filtrate was transferred to a separatory funnel
  5. customthe layers were separated
  6. extractionThe aqueous layer was extracted again with CHCl3
  7. customA white solid was obtained
  8. concentrationconcentrated to <100 mL
  9. filtrationA white precipitate was filtered
  10. filtrationthe mixture filtered again
  11. concentrationThe filtrate was concentrated again to <100 mL
  12. customan additional quanitity of white solid was obtained (1.80 g)

Sources & evidence

ORD record
ord-a3abf7be742a43f791616cfeec3161df
Source dataset
uspto-grants-2002_07
Patent number
US06426346B1

Reaction notes

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