反应详情

温度

85 °C

Sodium hydride (1.9 g, 79.17 mmol, 1.60 equiv) was added in several portions to the mixture of 5-chloro-1-methyl-1H-benzo[d][1,3]oxazine-2,4-dione in N,N-dimethylformamide from Step 2. Diethyl malonate (7.7 g, 48.07 mmol, 1.00 equiv) was then added dropwise to the stirred mixture over a period of about 30 minutes. The resulting solution was stirred at about 85° C. for about 1 hour, water (800 ml) was added, and the pH of the solution was adjusted to 2 with a solution of hydrochloric acid (5 mol/L). The resulting crude product was collected by filtration and then re-crystallized in ethanol to give the title product as a light yellow solid (2.5 g, yield: 18% 2 steps).

1. filtrationThe resulting crude product was collected by filtration
2. customre-crystallized in ethanol