Acetic Acid → 6-METHOXYQUINAZOLINE-2,4-DIOL

HRID 1520316Notes

Reaction equation

HRID 1520316 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][C:3]=1[C:4]([OH:6])=O.C(O)(=O)C.[O-:17][C:18]#[N:19].[K+].[OH-].[Na+]>O>[CH3:12][O:11][C:8]1[CH:7]=[C:3]2[C:2](=[CH:10][CH:9]=1)[NH:1][C:18](=[O:17])[NH:19][C:4]2=[O:6]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 14798Sodium HydroxideHCID 2779305-Methoxyanthranilic acidHCID 11378442Potassium cyanate

Product 1

HCID 103302006-METHOXYQUINAZOLINE-2,4-DIOLYield 65%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

2-Amino-5-methoxybenzoic acid (13.0 g, 77.8 mmol, 1.0 eq.) was suspended in water (200 mL) and glacial acetic acid (5.2 mL) at 35° C. A freshly prepared solution of potassium cyanate (8.21 g, 101.4 mmol, 1.3 eq.) in water (86 mL) was added dropwise to the stirred mixture. After 4 h, NaOH (104.0 g, 2600 mL, 33.4 eq.) was added in portions, keeping the reaction temperature below 40° C. A clear solution was obtained momentarily before a precipitate formed. After cooling, the precipitate was filtered off and dissolved in hot water which was acidified to pH 5. The precipitate was collected and washed with water, dried by lyophilization to afford 9.63 g of 6-methoxyquinazoline-2,4(1H, 3H)-dione as a white solid (65%). LCMS m/z=193.1 (M+1) (Method B) (retention time=1.22 min). 1H NMR (400 MHz, DMSO-d6): δ 11.26 (s, 1H), 11.01 (s, 1H), 7.31-7.25 (m, 2H), 7.10 (d, 1H, J=8.8 Hz), 3.77 (s, 3H).

Workup

  1. customat 35° C
  2. customthe reaction temperature below 40° C
  3. customA clear solution was obtained momentarily before a precipitate
  4. customformed
  5. temperatureAfter cooling
  6. filtrationthe precipitate was filtered off
  7. dissolutiondissolved in hot water which
  8. customThe precipitate was collected
  9. washwashed with water
  10. customdried by lyophilization

Sources & evidence

ORD record
ord-ed1b55b3ec4a4937a4a231326610b6d4
Source dataset
uspto-grants-2015_07
Patent number
US09073890B2

Reaction notes

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