Phosphorus oxychloride → 2-Chloro-6,7-dihydro-9,10-dimethoxy-4H-pyrimido[6,1-a]isoquinolin-4-one

HRID 435156Notes

Reaction equation

HRID 435156 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH2:11][CH2:12][N:13]2[C:20](=O)[CH2:19][C:17](=O)[NH:16][C:14]2=[O:15])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].P(Cl)(Cl)([Cl:24])=O>>[Cl:24][C:17]1[CH:19]=[C:20]2[C:6]3[C:5]([CH2:11][CH2:12][N:13]2[C:14](=[O:15])[N:16]=1)=[CH:4][C:3]([O:2][CH3:1])=[C:8]([O:9][CH3:10])[CH:7]=3

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 31526701-[2-(3,4-Dimethoxy-phenyl)-ethyl]-pyrimidine-2,4,6-trione

Product 1

HCID 46787202-Chloro-6,7-dihydro-9,10-dimethoxy-4H-pyrimido[6,1-a]isoquinolin-4-one

Procedure

A mixture of 1-(3,4-dimethoxyphenylethyl)barbituric acid (20.2 g) and phosphorus oxychloride (100 ml) is refluxed for 2.5 hours at 100°-110° C. The excess of phosphorus oxychloride is distilled. The residue is poured onto crushed ice and made basic with a cold solution of 30% aqueous sodium hydroxide. A yellow gummy precipitate is separated and extracted with chloroform. The extract is washed with water, dried over sodium sulfate and concentrated to dryness under reduced pressure. The residue is purified by passage over a silica gel column using chloroform as eluent to give the desired compound.

Workup

  1. temperatureis refluxed for 2.5 hours at 100°-110° C
  2. distillationThe excess of phosphorus oxychloride is distilled
  3. additionThe residue is poured
  4. customonto crushed ice
  5. customA yellow gummy precipitate is separated
  6. extractionextracted with chloroform
  7. washThe extract is washed with water
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated to dryness under reduced pressure
  10. customThe residue is purified by passage over a silica gel column

Sources & evidence

ORD record
ord-23566a1230e144ce805ae36dd1db962d
Source dataset
uspto-grants-1983_08
Patent number
US04400506

Reaction notes

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