反应详情

To a solution of N-(2-aminoethyl)-N-cyclopropyl-2-nitrobenzenesulfonamide (0.47 g, 1.7 mmol) and diisopropylethylamine (0.71 mL, 4.1 mmol) in tetrahydrofuran (15 mL) was added 4-nitrophenyl chloroformate (0.33 g, 1.7 mmol) at 0° C., and the mixture was stirred at room temperature for 1 hour. Hexahydro-1,1-diphenyl-3H-oxazolo[3,4-a]pyrazin-3-one (0.40 g, 1.4 mmol) was added thereto, and the mixture was stirred at room temperature for 60 hours. To the reaction solution was added ethyl acetate, and the resulting mixture was washed with 1 N hydrochloric acid, a 1 N aqueous sodium hydroxide solution, water and saturated brine, and dried over magnesium sulfate. The solid was filtered off, and the filtrate was concentrated. The residue was purified with silica gel column chromatography (hexane:ethyl acetate=98:2 to ethyl acetate). The fractions were collected and concentrated. The residue was washed with diethyl ether and collected by filtration to obtain the title compound (0.76 g, yield 92%).

1. stirringthe mixture was stirred at room temperature for 60 hours
2. washthe resulting mixture was washed with 1 N hydrochloric acid
3. dry with materiala 1 N aqueous sodium hydroxide solution, water and saturated brine, and dried over magnesium sulfate
4. filtrationThe solid was filtered off
5. concentrationthe filtrate was concentrated
6. customThe residue was purified with silica gel column chromatography (hexane:ethyl acetate=98:2 to ethyl acetate)
7. customThe fractions were collected
8. concentrationconcentrated
9. washThe residue was washed with diethyl ether
10. filtrationcollected by filtration