Phosphorus oxychloride → 2-Chloro-3-nitro-5-(trifluoromethyl)pyridine

HRID 2394345Notes

Reaction equation

HRID 2394345 reaction equation
O[C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][C:5]([C:11]([F:14])([F:13])[F:12])=[CH:4][N:3]=1.P(Cl)(Cl)([Cl:17])=O.P(Cl)(Cl)(Cl)(Cl)Cl>C(Cl)(Cl)Cl>[Cl:17][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][C:5]([C:11]([F:14])([F:13])[F:12])=[CH:4][N:3]=1

Participants

5

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 24819Phosphorus pentachlorideHCID 178526653HCID 178526653, compound

Product 1

HCID 47369502-Chloro-3-nitro-5-(trifluoromethyl)pyridine

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
80 °C

Procedure

2-Hydroxy-3-nitro-5-trifluoromethylpyridine (8.8 g, 42.3 mmol) was added to a mixture of phosphorous oxychloride (4.2 mL, 45.9 mmol) and phosphorous pentachloride (9.6 g, 46.1 mmol) at 60° C. The reaction mixture was then heated under nitrogen at 80° C. overnight. The resulting dark product mixture was allowed to cool to room temperature and was poured into ice/water. The mixture was extracted with ether and the ether extract was washed with water and brine. After drying over magnesium sulfate, the solvent was removed to leave a dark oil which was subjected to flash chromatography on silica gel eluting with chloroform. Fractions containing only the desired product were combined and concentrated to leave a brown oil (5.0 g, 52%). 1H NMR (DMSO-d6): δ9.20 (s, 1H), 9.07 (s, 1H).

Workup

  1. temperatureto cool to room temperature
  2. extractionThe mixture was extracted with ether
  3. extractionthe ether extract
  4. washwas washed with water and brine
  5. dry with materialAfter drying over magnesium sulfate
  6. customthe solvent was removed
  7. customto leave a dark oil which

Sources & evidence

ORD record
ord-c475c41aa07f42f198d8cccde58f898f
Source dataset
uspto-grants-1998_09
Patent number
US05811432

Reaction notes

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