Nitric Acid → 2-Chloro-4-nitropyridin-3-ol

HRID 1811551Notes

Reaction equation

HRID 1811551 reaction equation
[Cl:1][C:2]1[C:7]([OH:8])=[CH:6][CH:5]=[CH:4][N:3]=1.[N+:9]([O-])([OH:11])=[O:10]>S(=O)(=O)(O)O.O>[Cl:1][C:2]1[C:7]([OH:8])=[C:6]([N+:9]([O-:11])=[O:10])[CH:5]=[CH:4][N:3]=1

Participants

5

Reactant 2

HCID 944Nitric AcidHCID 811362-Chloro-3-pyridinol

Product 1

HCID 217660172-Chloro-4-nitropyridin-3-olYield 24%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1118Sulfuric AcidSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of 2-chloro-3-pyridinol (11.3 g, 87.2 mmol) in concentrated sulfuric acid (25 mL) was cooled in an ice-bath and a 1:1 mixture of nitric acid and sulfuric acid (25 mL) was added slowly. After everything was added, solution was stirred at 0° C. for 1 hour and then at room temperature for another hour. Mixture was diluted with water and extracted with methylene chloride. Organic phases were dried over magnesium sulfate, filtered, and concentrated. Residue was purified by column chromatography on silica gel (ethyl acetate/hexane 2:1→3:1) to give 2-chloro-4-nitro-pyridin-3-ol as a tanned solid (3.58 g, 24%). 1HNMR (CDCl3, 400 MHz) δ 10.5 (s, 2H), 8.14-8.13 (d, J=5.5 Hz, 1H), 7.88-7.87 (d, J=5.5 Hz, 1H).

Workup

  1. additionwas added slowly
  2. additionAfter everything was added
  3. waitat room temperature for another hour
  4. extractionextracted with methylene chloride
  5. dry with materialOrganic phases were dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customResidue was purified by column chromatography on silica gel (ethyl acetate/hexane 2:1→3:1)

Sources & evidence

ORD record
ord-4ee59bed4da249d0898a6006e5545d10
Source dataset
uspto-grants-2013_01
Patent number
US08362248B2

Reaction notes

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