反应详情

To a solution of isopropyl 2-isopropoxy-4-oxo-4,5-dihydrofuran-3-carboxylate (12.2 g, 53.6 mmol), which similarly prepared according to the procedure described in the Example 74, Third step using diisopropyl malonate and chloroacetyl chloride, in ethanol (45 mL), 4-aminomorpholine (5.7 mL, 59.2 mmol) was added at ambient temperature. The mixture was stirred for 18 h. The solvent was removed under reduced pressure, and the crude product was suspended in methyl tert-butyl ether, then the precipitate was collected by filtration, washed with methyl tert-butyl ether and hexane then dried to afford isopropyl 2-(morpholinoamino)-4-oxo-4,5-dihydrofuran-3-carboxylate as solid (11.2 g, y. 75%).

1. customThe solvent was removed under reduced pressure
2. filtrationthe precipitate was collected by filtration
3. washwashed with methyl tert-butyl ether and hexane
4. customthen dried