Phosphorus oxychloride → 5-Bromo-4-chloro-2-methylpyridine 1-oxide

HRID 2196407Notes

Reaction equation

HRID 2196407 reaction equation
[Br:1][C:2]1[C:3]([N+]([O-])=O)=[CH:4][C:5]([CH3:9])=[N+:6]([O-:8])[CH:7]=1.O=P(Cl)(Cl)[Cl:15]>C(Cl)Cl>[Br:1][C:2]1[C:3]([Cl:15])=[CH:4][C:5]([CH3:9])=[N+:6]([O-:8])[CH:7]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 123329085-Bromo-2-methyl-4-nitropyridine 1-oxide

Product 1

HCID 136827785-Bromo-4-chloro-2-methylpyridine 1-oxideYield 80%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 5-bromo-2-methyl-4-nitropyridine N-oxide (558 mg, 2.41 mmol) in DCM (3 mL) at 0° C. was added dropwise a solution of POCl3 (1.3 mL, 7.22 mmol) in DCM (3.2 mL). After 12 h at 25° C. the solution was added to ice, adjusted to pH ˜8 and extracted several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and purified via column chromatography (silica, 1.5% MeOH in DCM) yielding the title compound (426 mg, 80%) as a white solid: LCMS (ES) m/z=224 (M+H)+.

Workup

  1. additionAfter 12 h at 25° C. the solution was added to ice
  2. extractionextracted several times with DCM
  3. dry with materialThe combined organic fractions were dried over Na2SO4
  4. concentrationconcentrated
  5. custompurified via column chromatography (silica, 1.5% MeOH in DCM)

Sources & evidence

ORD record
ord-f97105be943e4580bb8e96dfe7eb6606
Source dataset
uspto-grants-2012_12
Patent number
US08338434B2

Reaction notes

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