反应详情

Step 1): A solution of 5-hydroxyanthranilic acid (500 mg, 3.26 mmol) and triphosgene (1.45 g, 4.9 mmol) in 1,4-dioxane (20 ml) was refluxed overnight. The reaction mixture was poured into H2O (30 ml), and then the precipitates were filtered and dried to give 6-hydroxy-1,2-dihydro-4H-3,1-benzoxazin-2,4-dione, 360 mg (62%).

1. filtrationthe precipitates were filtered
2. customdried