Nitric Acid → 5-Methoxy-2-methyl-4-nitropyridine 1-oxide

HRID 845532Notes

Reaction equation

HRID 845532 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([CH3:10])=[N+:7]([O-:9])[CH:8]=1.[N+:11]([O-])([OH:13])=[O:12]>>[CH3:1][O:2][C:3]1[C:4]([N+:11]([O-:13])=[O:12])=[CH:5][C:6]([CH3:10])=[N+:7]([O-:9])[CH:8]=1

Participants

3

Reactant 2

HCID 944Nitric Acid2×HCID 122140195-Methoxy-2-methyl-1-oxo-1lambda~5~-pyridine

Product 1

HCID 151634575-Methoxy-2-methyl-4-nitropyridine 1-oxideYield 87%

Conditions

Temperature
60 °C

Procedure

21.2 g of 5-methoxy-2-methylpyridine 1-oxide are metered into 35 ml of 65% strength nitric acid and warmed to 60° C. in a manner such that the temperature of the reaction mixture does not rise above 80° C. The mixture is stirred at 80° C. for 1 hour, a further 13 ml of 100% strength nitric acid are added to bring the reaction to completion and the mixture is stirred at 60°-70° C. for a further 2 hours. For working up, the mixture is poured onto 300 g of ice. The yellow precipitate which separates out is filtered off over a suction filter, washed with water and dried. The dry solid is boiled up with 200 ml of methylene chloride, filtered off and dried. Further TLC-pure product is isolated by concentration of the filtrate. 22.3 g (87% of theory) of 5-methoxy-2-methyl-4-nitropyridine 1oxide of m.p. 201°-202° C. are obtained as yellow crystals.

Workup

  1. customdoes not rise above 80° C
  2. customthe reaction to completion
  3. stirringthe mixture is stirred at 60°-70° C. for a further 2 hours
  4. filtrationThe yellow precipitate which separates out is filtered off over a suction
  5. filtrationfilter
  6. washwashed with water
  7. customdried
  8. filtrationfiltered off
  9. customdried
  10. customFurther TLC-pure product is isolated by concentration of the filtrate

Sources & evidence

ORD record
ord-839f5bcebb5341dea39cfec423cc8242
Source dataset
uspto-grants-1988_07
Patent number
US04758579

Reaction notes

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