Ammonia → 2-Methoxy-4-nitropyridine-n-oxide

HRID 1974831

Reaction equation

HRID 1974831 reaction equation
Cl.[CH3:2][O:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][N+:5]=1[O-:10].[N+:11]([O-])([OH:13])=[O:12].N>S(=O)(=O)(O)O>[CH3:2][O:3][C:4]1[CH:9]=[C:8]([N+:11]([O-:13])=[O:12])[CH:7]=[CH:6][N+:5]=1[O-:10]

Participants

5

Reactant 3

HCID 222AmmoniaHCID 944Nitric AcidHCID 125620762-methoxypyridine N-oxide hydrochloride

Product 1

HCID 5792072-Methoxy-4-nitropyridine-n-oxide

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent2×

Procedure

30 ml of concentrated sulfuric acid, cooled to 0° C., are added to 15.5 g of 2-methoxypyridine N-oxide hydrochloride, after which 42 ml of fuming nitric acid and 14 ml of concentrated sulfuric acid are added dropwise at 0° C. After the temperature has been allowed to rise, the reaction mixture is heated for 3 hours at 90°-100° C. and is then cooled and poured onto 50 g of ice. It is neutralized to pH 7 by the addition of concentrated aqueous ammonia at a temperature below 10° C. The aqueous phase is extracted 6 times with methylene chloride, the organic phase is then dried over sodium sulfate and concentrated and 11 g of a yellow solid corresponding to a mixture of 2-methoxy-4-nitropyridine N-oxide and 2-methoxy-5-nitropyridine N-oxide are recovered. The 2 products are separated by chromatography on silica using a methylene chloride/methanol mixture (95/5) as the eluent. 6.3 g of 2-methoxy-4-nitropyridine N-oxide are collected.

Workup

  1. temperaturethe reaction mixture is heated for 3 hours at 90°-100° C.
  2. temperatureis then cooled
  3. extractionThe aqueous phase is extracted 6 times with methylene chloride
  4. dry with materialthe organic phase is then dried over sodium sulfate
  5. concentrationconcentrated
  6. addition11 g of a yellow solid corresponding to a mixture of 2-methoxy-4-nitropyridine N-oxide and 2-methoxy-5-nitropyridine N-oxide
  7. customare recovered
  8. customThe 2 products are separated by chromatography on silica using a methylene chloride/methanol mixture (95/5) as the eluent
  9. custom6.3 g of 2-methoxy-4-nitropyridine N-oxide are collected

Sources & evidence

ORD record
ord-bd7cf4875ee54beab717671be826d4ec
Source dataset
uspto-grants-1994_02
Patent number
US05284838

Linked notes

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