Phosphorus oxychloride → 3-Bromo-2-chloro-5-methylpyridine

HRID 1766441Notes

Reaction equation

HRID 1766441 reaction equation
[Br:1][C:2]1[C:3](=O)[NH:4][CH:5]=[C:6]([CH3:8])[CH:7]=1.P(Cl)(Cl)([Cl:12])=O>>[Br:1][C:2]1[C:3]([Cl:12])=[N:4][CH:5]=[C:6]([CH3:8])[CH:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 37252613-Bromo-2-hydroxy-5-methylpyridine

Product 1

HCID 2854373-Bromo-2-chloro-5-methylpyridine

Procedure

A mixture of 3-bromo-5-methyl-2(1H)-pyridinone (25 g, 0.13 mol) and phosphorus oxychloride (500 mL) was boiled with stirring for 20 h. Phosphorus oxychloride was removed by distillation and the residue was poured onto ice/water (800 mL). The mixture was adjusted to pH 8.5 with 2 N sodium hydroxide solution and extracted with diethyl ether. Organic phases were pooled, dried with Na2SO4 and the solvent was evaporated. The residue, 23.4 g of the title compound as a greyish solid was introduced into the next step without purification, MS (EI) 204.9, 206.9 (M)+.

Workup

  1. customPhosphorus oxychloride was removed by distillation
  2. additionthe residue was poured onto ice/water (800 mL)
  3. extractionextracted with diethyl ether
  4. dry with materialdried with Na2SO4
  5. customthe solvent was evaporated
  6. additionThe residue, 23.4 g of the title compound as a greyish solid was introduced into the next step without purification, MS (EI) 204.9, 206.9 (M)+

Sources & evidence

ORD record
ord-9a3ffe62bd06419fbab98b006e11eba2
Source dataset
uspto-grants-2007_06
Patent number
US07229999B2

Reaction notes

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