Acetic Acid → 5-Chloroquinazoline-2,4-diol

Participants

Reaction Steps

To a solution of 6-chloroanthranilic acid (1.72 g, 10 mmol) and NaOH (0.40 g, 10 mmol) in water (15 mL) was added sodium cyanate (0.72 g, 11 mmol), followed by acetic acid (0.66 g, 11 mmol). The solution was stirred for 9 h, and then acidified with conc. HCl. The precipitate was filtered off and washed with water. The wet solid was added to a solution of NaOH (8.0 g, 200 mmol) in water (60 mL) and stirred for 20 h. The precipitate was filtered off and suspended in water (80 mL), then heated to boiling and acidified with 50% H2SO4. The cooled mixture was filtered, the solid washed well with water and dried to give 5-chloroquinazolin-2,4-dione (1.42 g, 72%).

Provenance & Evidence