Hydrochloric Acid → 2-(2-methoxyphenyl)-3H-quinazolin-4-one

Participants

Reaction Conditions

Reaction Steps

To a cooled (0-5° C.) mixture of anthranilamide (350 g, 2.57 mol) and triethylamine (286 g, 2.83 mol) in THF (2.5 L) was added dropwise o-anisoyl chloride (437 g, 2.57 mol) while maintaining the temperature between 0-20° C. The resulting suspension was stirred at room temperature overnight. The solvent was evaporated in vacuo, and the residue was washed several times with water. The wet residue was suspended in 2 M aq. NaOH (13 L), and the mixture was heated to reflux. After 20 minutes a clear solution was obtained. After 1 h of reflux the clear solution was cooled in an ice water bath and then acidified to pH 6 with conc. aq. HCl. The suspension was filtered, and the residue was washed thoroughly with water. The white solid was dried by azeotropic distillation with toluene. 2-(2-Methoxyphenyl)quinazolin-4(3H)-one (567 g) was obtained in 82%. 1H-NMR (200 MHz, Me2SO-d6): δ 3.90 (s, 3 H), 7.20 (m, 2 H), 7.60 (t, 2 H), 7.85 (m, 3 H), 8.20 (d, 1 H), 12.20 (s, 1 H).

Provenance & Evidence