反应详情

4 ml of 2-chloroethylisocyanate were added, under stirring at ambient temperature, to a solution of 3.9 g of 8-amino-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran in 52 ml of anhydrous dimethylformamide. Stirring was continued at 70° C. for 5 hours. Water was added to the reaction mixture, which was then extracted with ethyl acetate. The organic phase was evaporated to dryness in vacuo. The residue was suspended in diethyl ether under stirring. The title product was then filtered off and recrystallized from methanol. Yield 3.74 g, m.p. 213°-214° C.

1. extractionwas then extracted with ethyl acetate
2. customThe organic phase was evaporated to dryness in vacuo
3. stirringunder stirring
4. filtrationThe title product was then filtered off
5. customrecrystallized from methanol