反应详情

温度

-20 °C

To a stirred solution of 1-tert-butyl-1,2,3,4-tetrahydro-2,3-dioxoquinoxaline (6.54 g, 30 mmol) in dry dimethylformamide (DMF) (30 ml) under nitrogen was added sodium hydride (80% in oil, 9.6 g, 32 mmol). After stirring for 10 min. the solution was cooled to -20° C. and diethyl chlorophosphate (5.6 ml, 39 mmol) was added. The mixture was allowed to reach room temperature and then cooled to -30° C., whereafter 5-isocyanomethyl-3-methylisoxazole (3.0 g, 25 mmol) and finally a solution of potassium tert-butoxide (3.0 g, 26 mmol) in dry DMF (30 ml) was added keeping the temperature below -20° C. The reaction mixture was warmed to room temperature, acidified with acetic acid (1 ml) and evaporated in vacuo. The residue was triturated with water and ether, and the resulting precipitate was filtered off and partitioned between 0.5 M aqueous sodium hydroxide (50 ml) and dichloromethane (50 ml). The organic layer was filtered through celite, dried, and evaporated to give the title compound, m.p. 395° C. (Compound 17).

1. customto reach room temperature
2. customthe temperature below -20° C
3. temperatureThe reaction mixture was warmed to room temperature
4. customevaporated in vacuo
5. customThe residue was triturated with water and ether
6. filtrationthe resulting precipitate was filtered off
7. custompartitioned between 0.5 M aqueous sodium hydroxide (50 ml) and dichloromethane (50 ml)
8. filtrationThe organic layer was filtered through celite
9. customdried
10. customevaporated