Sodium Hydroxide → 3-Fluoro-2-methylpyridine 1-oxide

HRID 1655225Notes

Reaction equation

HRID 1655225 reaction equation
[N:1]([O-:3])=O.[Na+].N[C:6]1[C:7]([CH3:12])=N[CH:9]=[CH:10][CH:11]=1.[OH-].[Na+].[F:15][B-](F)(F)F.[H+]>>[CH3:12][C:7]1[C:6]([F:15])=[CH:11][CH:10]=[CH:9][N+:1]=1[O-:3]

Participants

5

Reactant 4

HCID 14798Sodium HydroxideHCID 28118Tetrafluoroboric acidHCID 5726163-Amino-2-methylpyridineHCID 23668193Sodium Nitrite

Product 1

HCID 197911603-Fluoro-2-methylpyridine 1-oxide

Procedure

Sodium nitrite (15.3 g) was added to a stirred solution of 3-amino-2-picoline (20 g) in 40% fluoroboric acid (215 ml) at -5° to -10°. The mixture was stirred for 2 hours at -10° followed by a further 2 hours at room temperature, after which time, the solution was basified (NaOH) and extracted with dichloromethane. The extracts were back-washed with water (pH 6 HCl) to remove some unreacted amine and, after drying (K2CO3), m-chloroperbenzoic acid (35.7 g) was added and the mixture allowed to stand for 16 hours. Ammonia gas was passed through the solution and the precipitated benzoate salts filtered off. The filtrate was evaporated to dryness to give 2-methyl-3-fluoropyridine-N-oxide (13.36 g) m.p. softens 55° melts 80°.

Workup

  1. waitfollowed by a further 2 hours at room temperature
  2. extractionextracted with dichloromethane
  3. washThe extracts were back-washed with water (pH 6 HCl)
  4. customto remove some unreacted amine
  5. dry with materialafter drying (K2CO3), m-chloroperbenzoic acid (35.7 g)
  6. additionwas added
  7. waitto stand for 16 hours
  8. filtrationthe precipitated benzoate salts filtered off
  9. customThe filtrate was evaporated to dryness

Sources & evidence

ORD record
ord-dc2a73951bca498493480e7f4b1f252a
Source dataset
uspto-grants-1993_10
Patent number
US05250527

Reaction notes

Loading…