Phosphorus oxychloride → 4-Chloro-5-nitro-2-(trifluoromethyl)pyridine

HRID 895563Notes

Reaction equation

HRID 895563 reaction equation
[N+:1]([C:4]1[C:5](O)=[CH:6][C:7]([C:10]([F:13])([F:12])[F:11])=[N:8][CH:9]=1)([O-:3])=[O:2].P(Cl)(Cl)(Cl)(Cl)[Cl:16].O=P(Cl)(Cl)Cl>>[Cl:16][C:5]1[C:4]([N+:1]([O-:3])=[O:2])=[CH:9][N:8]=[C:7]([C:10]([F:13])([F:12])[F:11])[CH:6]=1

Participants

4

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 24819Phosphorus pentachlorideHCID 178526809HCID 178526809, compound

Product 1

HCID 223800514-Chloro-5-nitro-2-(trifluoromethyl)pyridine

Conditions

Temperature
80 °C

Procedure

The crude 5-nitro-2-trifluoromethyl-pyridin-4-ol (3.4 g, 16.3 mmmol) was treated with PCl5 (5.2 g, 24.97 mmol) and POCl3 (7 mL, 24.49 mmol). The resulting mixture is heated at 80° C. for 18 h, cooled and poured into ice-cold water, and extracted with CH2Cl2. The combined organic phase is washed successively with saturated aqueous NaHCO3, water, brine, dried over Na2SO4, and concentrated in vacuo to afford 4-Chloro-5-nitro-2-trifluoromethyl-pyridine as an yellow oil. 1H NMR (300 MHz, CDCl3): δ 9.17 (s, 1H), 7.9 (s, 1H).

Workup

  1. temperaturecooled
  2. additionpoured into ice-cold water
  3. extractionextracted with CH2Cl2
  4. washThe combined organic phase is washed successively with saturated aqueous NaHCO3, water, brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-2fb58417bc2e4e50924895bc8e015078
Source dataset
uspto-grants-2005_07
Patent number
US06916819B2

Reaction notes

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