Phosphorus oxychloride → 6-Chloro-1,3-dimethyl-2,4(1H,3H)-pyrimidinedione

HRID 648888Notes

Reaction equation

HRID 648888 reaction equation
[CH3:1][N:2]1[C:9](=O)[CH2:8][C:6](=[O:7])[N:5]([CH3:11])[C:3]1=[O:4].P(Cl)(Cl)([Cl:14])=O>O>[Cl:14][C:9]1[N:2]([CH3:1])[C:3](=[O:4])[N:5]([CH3:11])[C:6](=[O:7])[CH:8]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 69860Dimethylbarbituric acid

Product 1

HCID 814426-Chloro-1,3-dimethyl-2,4(1H,3H)-pyrimidinedione

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 110 g of the 1,3-dimethylbarbituric acid was added 32 ml of water, and 800 ml of phosphorus oxychloride was added dropwise thereto. After heating at reflux for 1.5 hours, the phosphorus oxychloride was distilled away under normal pressure, and the residue, while hot, was poured onto ice. The precipitated crystals were collected by filtration. The filtrate was extracted three times with chloroform and dried over anhydrous sodium sulfate. The chloroform was then removed by distillation, and the resulting residue was combined with the aforesaid crystals. Recrystallization from water gave 80 g of 6-chloro-1,3-dimethyluracil.

Workup

  1. additionwas added dropwise
  2. temperatureAfter heating
  3. temperatureat reflux for 1.5 hours
  4. distillationthe phosphorus oxychloride was distilled away under normal pressure
  5. additionthe residue, while hot, was poured onto ice
  6. filtrationThe precipitated crystals were collected by filtration
  7. extractionThe filtrate was extracted three times with chloroform
  8. dry with materialdried over anhydrous sodium sulfate
  9. customThe chloroform was then removed by distillation
  10. customRecrystallization from water

Sources & evidence

ORD record
ord-2188cdefb9dd4f449ba9968f6d9127fa
Source dataset
uspto-grants-1988_04
Patent number
US04737442

Reaction notes

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