Acetic Acid → 8-Methoxyquinazoline-2,4-diol

HRID 973559Notes

Reaction equation

HRID 973559 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[CH:10][CH:9]=[C:5]([C:6]([OH:8])=O)[C:4]=1[NH2:12].C(O)(=O)C.[O-:17][C:18]#[N:19].[K+].[OH-].[Na+]>O>[CH3:1][O:2][C:3]1[CH:11]=[CH:10][CH:9]=[C:5]2[C:4]=1[NH:12][C:18](=[O:17])[NH:19][C:6]2=[O:8]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 14798Sodium HydroxideHCID 2557202-Amino-3-methoxybenzoic acidHCID 11378442Potassium cyanate

Product 1

HCID 103525548-Methoxyquinazoline-2,4-diol

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

3-Methoxyanthranilic acid (6 g, 0.036 mol) was suspended in water (200 ml, 35°) and glacial acetic acid (2.2 ml). A freshly prepared solution of potassium cyanate (3.7 g, 0.046 mol) in water (20 ml) was added dropwise to the stirred mixture. After 2 hours, sodium hydroxide (48.5 g 1.21 mol) was added in portions keeping the temperature below 40°. A clear solution was obtained momentarily before precipitating the hydrated sodium salt. After cooling, the precipitate was filtered off, dissolved in hot water which was acidified to pH 5, causing precipitation of 8-methoxy-2,4-quinazolinedione (4.6 g, 58%) m.p. 255°-257°.

Workup

  1. customthe temperature below 40°
  2. customA clear solution was obtained momentarily
  3. custombefore precipitating the hydrated sodium salt
  4. temperatureAfter cooling
  5. filtrationthe precipitate was filtered off
  6. dissolutiondissolved in hot water which
  7. customprecipitation of 8-methoxy-2,4-quinazolinedione (4.6 g, 58%) m.p. 255°-257°

Sources & evidence

ORD record
ord-e1da7527745b47f3a3cd60c049ba9b12
Source dataset
uspto-grants-1991_11
Patent number
US05064833

Reaction notes

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