反应详情

Iodomethane (1.4 mL) and potassium carbonate (1.6 g) were added to an acetonitrile (5.0 mL) solution of N2-(t-butoxycarbonyl)-N,N2,O-trimethyl-3-oxoserinamide (Intermediate 4-2, 2.0 g), and the mixture was stirred for 20 hours at room temperature under closed conditions. Iodomethane (2.8 mL) was added, and the mixture was stirred for 3 days at room temperature under closed conditions. Further, iodomethane (2.8 mL) was added, and the mixture was stirred for 1 day at room temperature under closed conditions, and then stirred for 9 hours at 50° C. After the reaction mixture was stirred for 14 hours at room temperature, potassium carbonate was filtered out. Then, the system was washed with ethyl acetate, and the reaction mixture was concentrated. The resulting residue was purified by OH type silica gel column chromatography (gradient elution with hexane/ethyl acetate=70/30→100/0) to obtain N2-(t-butoxycarbonyl)-N,N2,O,2-tetramethyl-3-oxoserinamide (Intermediate 8-2, yellow oil) (1.5 g, 78%).

1. stirringthe mixture was stirred for 3 days at room temperature under closed conditions
2. stirringthe mixture was stirred for 1 day at room temperature under closed conditions
3. stirringstirred for 9 hours at 50° C
4. stirringAfter the reaction mixture was stirred for 14 hours at room temperature
5. filtrationpotassium carbonate was filtered out
6. washThen, the system was washed with ethyl acetate
7. concentrationthe reaction mixture was concentrated
8. customThe resulting residue was purified by OH type silica gel column chromatography (gradient elution with hexane/ethyl acetate=70/30→100/0)