Nitric Acid → 3-Methoxy-4-nitro-1-oxo-1lambda~5~-pyridine

HRID 266913

Reaction equation

HRID 266913 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[N+:5]([O-:9])[CH:6]=[CH:7][CH:8]=1.OS(O)(=O)=O.[N+:15]([O-])([OH:17])=[O:16].[OH-].[Na+]>>[CH3:1][O:2][C:3]1[CH:4]=[N+:5]([O-:9])[CH:6]=[CH:7][C:8]=1[N+:15]([O-:17])=[O:16]

Participants

5

Reactant 4

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 139850Pyridine, 3-methoxy-, 1-oxide

Product 1

HCID 147627103-Methoxy-4-nitro-1-oxo-1lambda~5~-pyridineYield 41%

Conditions

Temperature
75 °C

Procedure

A solution of 3-methoxypyridine-N-oxide (24 g, 0.19 mol) and con. H2SO4 (45 ml)was carefully prepared by adding the acid slowly to the solid N-oxide using an ice bath for cooling. After solution is effected, it is rapidly stirred and fuming nitric acid (45 ml) is added over 15 min. The reaction mixture was warmed to 75° C. for 2.5 hours. The contents were poured onto ice and neutralized to pH 9 with cooling using 50% NaOH. The mixture was extracted three times with CH2Cl2, dried, (Na2SO4) and solvent evaporated under reduced pressure to produce an oil. The crude product was chromatographed on silica gel using CH2Cl2 /MeOH (99:1) as the eluent to give 17.5 g (41%) of the pure product as a crystalline solid, m.p. 125°-127° C. The structural assignment is supported by the proton NMR spectrum.

Workup

  1. temperaturefor cooling
  2. additionThe contents were poured onto ice and neutralized to pH 9
  3. temperaturewith cooling
  4. extractionThe mixture was extracted three times with CH2Cl2
  5. customdried
  6. custom(Na2SO4) and solvent evaporated under reduced pressure
  7. customto produce an oil
  8. customThe crude product was chromatographed on silica gel

Sources & evidence

ORD record
ord-7c8328e039e743a59011498e4f254e9c
Source dataset
uspto-grants-1997_07
Patent number
US05652363

Linked notes

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