Sodium Hydroxide → 2-methyl-3-fluoro-4-chloro-pyridine-N-oxide

HRID 1655227Notes

Reaction equation

HRID 1655227 reaction equation
P(Cl)(Cl)([Cl:3])=O.[CH3:6][C:7]1[C:12]([F:13])=[C:11]([N+]([O-])=O)[CH:10]=[CH:9][N+:8]=1[O-:17].[OH-].[Na+]>ClCCl>[CH3:6][C:7]1[C:12]([F:13])=[C:11]([Cl:3])[CH:10]=[CH:9][N+:8]=1[O-:17]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 197911692-methyl-3-fluoro-4-nitropyridine-N-oxide

Product 1

HCID 197911332-methyl-3-fluoro-4-chloro-pyridine-N-oxide

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Phosphoryl chloride (19 ml) in dichloromethane (50 ml) was added dropwise to a stirred solution of 2-methyl-3-fluoro-4-nitropyridine-N-oxide (12 g) in dichloromethane (50 ml). The reaction mixture was heated under reflux for a total of 8 hours. After cooling and pouring onto ice, the mixture was basified (NaOH) to pH 9 and extracted with dichloromethane. After drying (K2CO3) and removal of solvent, the crude product was purified by column chromatography (silica gel; 1% MeOH/CHCl3) to give 2-methyl-3-fluoro-4-chloro-pyridine-N-oxide (6.78 g) m.p. 63°-65°.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for a total of 8 hours
  3. temperatureAfter cooling
  4. additionpouring onto ice
  5. extractionextracted with dichloromethane
  6. customAfter drying
  7. custom(K2CO3) and removal of solvent
  8. customthe crude product was purified by column chromatography (silica gel; 1% MeOH/CHCl3)

Sources & evidence

ORD record
ord-b2125cdc26e5405f92576f962459326b
Source dataset
uspto-grants-1993_10
Patent number
US05250527

Reaction notes

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