Dimethyl Sulfate → 5,6-Dimethoxy-1,3-dimethylquinazolin-2,4(1H, 3H)-dione

HRID 980887Notes

Reaction equation

HRID 980887 reaction equation
S(OC)(O[CH3:5])(=O)=O.[CH3:8][O:9][C:10]1[C:19]([O:20][CH3:21])=[CH:18][CH:17]=[C:16]2[C:11]=1[C:12](=[O:24])[N:13]([CH3:23])[C:14](=[O:22])[NH:15]2.[OH-].[K+]>>[CH3:8][O:9][C:10]1[C:19]([O:20][CH3:21])=[CH:18][CH:17]=[C:16]2[C:11]=1[C:12](=[O:24])[N:13]([CH3:23])[C:14](=[O:22])[N:15]2[CH3:5]

Participants

4

Reactant 3

HCID 6497Dimethyl SulfateHCID 14797Potassium HydroxideHCID 137720135,6-Dimethoxy-3-methylquinazolin-2,4(1H, 3H)-dione

Product 1

HCID 137720175,6-Dimethoxy-1,3-dimethylquinazolin-2,4(1H, 3H)-dione

Procedure

Dimethyl sulfate (2.5 ml, 3.33 g, 26.40 mM) was added to 5,6-dimethoxy-3-methylquinazolin-2,4(1H, 3H)-dione (2.0 g, 8.47 mM). The mixture was heated at 80°-85° C. (oil bath temperature) for five minutes. Aqueous KOH (7.9 ml of a 5N solution) was added gradually until the pH of the reaction mixture remained basic. The reaction mixture was cooled and the resulting solid filtered, washed with a small amount of H2O and dried to afford the title compound as a white solid; 1.74 g (80.6%); mp 136°-139° C.; CF3COOH(TMS) 7.75 (d, 1H, J7,8 =9.0Hz, 7-H), 7.33 (d, 1H, J8,7 =9.0Hz, 8-H), 4.28 (s, 3H, 5 or 6-OCH3), 4.07 (s, 3H, 5 or 6-OCH3), 3.80 (s, 3H, 1 or 3-N-CH3), 3.73 (s, 3H, 1 or 3-N-CH3); M+ 250.

Workup

  1. temperatureThe mixture was heated at 80°-85° C. (oil bath temperature) for five minutes
  2. temperatureThe reaction mixture was cooled
  3. filtrationthe resulting solid filtered
  4. washwashed with a small amount of H2O
  5. customdried

Sources & evidence

ORD record
ord-7c9c807d017b471c943bd0294e079e15
Source dataset
uspto-grants-1987_01
Patent number
US04639518

Reaction notes

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