Potassium Permanganate → 3-Amino-6-chloropyridine-2-carboxylic acid

HRID 887727Notes

Reaction equation

HRID 887727 reaction equation
[NH2:1][C:2]1[C:3]([C:9]2[O:10]C=CC=2)=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1.[Mn]([O-])(=O)(=O)=[O:15].[K+]>CC(C)=O.O>[NH2:1][C:2]1[C:3]([C:9]([OH:10])=[O:15])=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 516875Potassium Permanganate2×HCID 593554186-Chloro-2-(2-furanyl)-3-pyridinamine

Product 1

HCID 533934343-Amino-6-chloropyridine-2-carboxylic acidYield 67.7%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent2×

Conditions

Temperature
0 °C

Procedure

3-Amino-6-chloro-2-(2-furanyl)pyridine (1.06 g) was dissolved in acetone (25 mL) and cooled in an ice bath to 0° C. A solution prepared of potassium permanganate (2.57 g) in water (40 mL) was added drop wise to this solution. After complete addition, the reaction mixture was allowed to warm to room temperature and stirred for hours. The mixture was cooled again to 0° C. and a second portion of potassium permanganate (858 mg) in water (15 mL) was added and the cool bath removed. After stirring for 2 hours, the reaction mixture was filtered through a pad of celite, the filter cake was washed carefully with water, methanol and ethyl acetate and concentrated to approx. 20 mL on a rotary evaporator. 2N Sodium hydroxide solution was added to adjust the pH-value to −12 and the aqueous layer was washed 2× with MTB-ether. The aqueous layer was adjusted to pH ˜2 by addition of 6N hydrochloric acid and extracted 3× with MTB-ether. The combined organic layer was washed with brine, dried over MgSO4 and concentrated in vacuum to afford 636 mg of the title compound of the formula

Workup

  1. additionwas added drop wise to this solution
  2. additionAfter complete addition
  3. temperatureto warm to room temperature
  4. temperatureThe mixture was cooled again to 0° C.
  5. customthe cool bath removed
  6. stirringAfter stirring for 2 hours
  7. filtrationthe reaction mixture was filtered through a pad of celite
  8. washthe filter cake was washed carefully with water, methanol and ethyl acetate
  9. concentrationconcentrated to approx. 20 mL on a rotary evaporator
  10. addition2N Sodium hydroxide solution was added
  11. washthe aqueous layer was washed 2× with MTB-ether
  12. additionThe aqueous layer was adjusted to pH ˜2 by addition of 6N hydrochloric acid
  13. extractionextracted 3× with MTB-ether
  14. washThe combined organic layer was washed with brine
  15. dry with materialdried over MgSO4
  16. concentrationconcentrated in vacuum

Sources & evidence

ORD record
ord-77dde900d7224338839c78676b81614b
Source dataset
uspto-grants-2012_08
Patent number
US08247431B2

Reaction notes

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