Phosphorus oxychloride → 4-Chloro-6-isopropyl-3-nitro-1H-pyridin-2-one

HRID 895548Notes

Reaction equation

HRID 895548 reaction equation
O[C:2]1[CH:7]=[C:6]([CH:8]([CH3:10])[CH3:9])[NH:5][C:4](=[O:11])[C:3]=1[N+:12]([O-:14])=[O:13].O=P(Cl)(Cl)[Cl:17]>CC#N.[Cl-].C([N+](CC)(CC)CC)C1C=CC=CC=1>[Cl:17][C:2]1[CH:7]=[C:6]([CH:8]([CH3:10])[CH3:9])[NH:5][C:4](=[O:11])[C:3]=1[N+:12]([O-:14])=[O:13]

Participants

5

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 546965894-hydroxy-6-isopropyl-3-nitro-1H-pyridin-2-one

Product 1

HCID 223800994-Chloro-6-isopropyl-3-nitro-1H-pyridin-2-one

Reagents, catalysts & solvents 2

HCID 66133Benzyl triethylammonium chlorideCatalystHCID 6342AcetonitrileSolvent

Procedure

To a suspension of 4-hydroxy-6-isopropyl-3-nitro-1H-pyridin-2-one (3.02 g, 15.2 mmol) in CH3CN (60 mL) at room temperature is added benzyltriethylammonium chloride (13.88 g, 61.0 mmol). The mixture is stirred at room temperature for 5-10 min, and then POCl3 (6.25 mL, 67.1 mmol) is added. The reaction mixture is stirred at room temperature for 15 min and then at reflux for 1 h. After cooling, the reaction mixture is concentrated in vacuo. The flask is then placed in an ice bath, and the residue treated with H2O (˜60 mL). The mixture is stirred for 4 h while slowly warming to rt. The solid that forms over this period of time is collected by filtration and then washed with H2O and a small amount of hexanes. 4-Chloro-6-isopropyl-3-nitro-1H-pyridin-2-one is obtained as a yellow solid. 1H NMR (CDCl3, 300 MHz) δ 13.13 (br s, 1H), 6.24 (s, 1H), 2.89 (sept, J=6.9 Hz, 1H), 1.31 (d, J=6.9 Hz, 6H) ppm.

Workup

  1. stirringThe reaction mixture is stirred at room temperature for 15 min
  2. temperatureat reflux for 1 h
  3. temperatureAfter cooling
  4. concentrationthe reaction mixture is concentrated in vacuo
  5. customThe flask is then placed in an ice bath
  6. additionthe residue treated with H2O (˜60 mL)
  7. stirringThe mixture is stirred for 4 h
  8. temperaturewhile slowly warming to rt
  9. filtrationThe solid that forms over this period of time is collected by filtration
  10. washwashed with H2O

Sources & evidence

ORD record
ord-081f8361f68f4b1a82270144ba02d335
Source dataset
uspto-grants-2005_07
Patent number
US06916819B2

Reaction notes

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