反应详情

To a solution of tert-butyl[(4′R)-6′-{[(5-methoxypyrazin-2-yl)carbonyl]amino}-2′,2′-dimethyldispiro[cyclopropane-1,3′-chromene-4′,4″-[1,3]oxazol]-2″-yl]carbamate (392 mg, 0.769 mmol) in chloroform (3 ml) was added trifluoroacetic acid (1.8 ml), and the mixture was stirred at room temperature for 2 hours. The mixture was concentrated in vacuo, and the residue was purified by silica gel column chromatography (precolumn: NH-silica gel, main column: neutral silica gel, chloroform/methanol=10:0-10:1). To the purified product was added a mixture of hexane/ethyl acetate (4:1) and the mixture was stirred at room temperature over night. The precipitate was collected, washed with mixture of hexane/ethyl acetate (4:1), and dried in vacuo to afford N-[(4′R)-2″-amino-2′,2′-dimethyldispiro[cyclopropane-1,3′-chromene-4′,4″-[1,3]oxazol]-6′-yl]-5-me thoxypyrazine-2-carboxamide (246 mg).

1. concentrationThe mixture was concentrated in vacuo
2. customthe residue was purified by silica gel column chromatography (precolumn: NH-silica gel, main column: neutral silica gel, chloroform/methanol=10:0-10:1)
3. additionTo the purified product was added
4. additiona mixture of hexane/ethyl acetate (4:1)
5. stirringthe mixture was stirred at room temperature over night
6. customThe precipitate was collected
7. washwashed with mixture of hexane/ethyl acetate (4:1)
8. customdried in vacuo