Phosphorus oxychloride → 4-Chloro-6,7-dimethoxyquinazoline

HRID 276794Notes

Reaction equation

HRID 276794 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]=[CH:8][NH:7][C:6]2=O.O=P(Cl)(Cl)[Cl:18]>>[Cl:18][C:6]1[C:5]2[C:10](=[CH:11][C:12]([O:13][CH3:14])=[C:3]([O:2][CH3:1])[CH:4]=2)[N:9]=[CH:8][N:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 1354950166,7-Dimethoxy-3H-quinazolin-4-one

Product 1

HCID 27693644-Chloro-6,7-dimethoxyquinazolineYield 83%

Procedure

A suspension of 6,7-dimethoxyquinazoline-4(3H)-one 4 (12.36 g, 60 mmol) in POCl3 (250 mL) was heated under reflux for 4 hr, when a clear solution was obtained. The POCl3 was removed under reduced pressure, and the residue was dissolved in a mixture of CH2Cl2 and aqueous Na2CO3. The organic layer was dried and the solvent removed to give 4-chloro-6,7-dimethoxyquinazoline 5 (11.2 g, 83%); m.p. 259.0-263.0° C.; 1H NMR (DMSO-d6): d 8.75(s, 1H, 2-H), 7.53(s, 1H, 5-H), 7.25(s, 1H, 8H), 3.91(s, 3H, —OCH3), 3.89(s, 3H, —OCH3); IR (KBr) umax: 2963, 2834, 1880, 1612, 1555, 1503, 1339, 1153, 962 cm−1. GC/MS m/z 224(M+, 100), 209(M+ —CH3, 9.4), 189(19.39), (69(10.55).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 4 hr
  3. customwhen a clear solution was obtained
  4. customThe POCl3 was removed under reduced pressure
  5. dissolutionthe residue was dissolved in a mixture of CH2Cl2 and aqueous Na2CO3
  6. customThe organic layer was dried
  7. customthe solvent removed

Sources & evidence

ORD record
ord-559b4b158a3446968ccd7acd5ad6e2ce
Source dataset
uspto-grants-2002_03
Patent number
US06355645B2

Reaction notes

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