反应详情

Spiro[4H-3,1-benzoxazine-4,4′-piperidin]-2(1H)-one (A4) (353 mg, 1.62 mmol) was dissolved in anhydrous 1,2-dichloroethane (10 mL) and treated with cycloheptanone (iiia) (273 mg, 2.43 mmol), followed by glacial acetic acid (195 mg, 3.24 mmol) and sodium triacetoxyborohydride (687 mg, 3.24 mmol). The reaction was stirred at room temperature under nitrogen for 90 hours. The reaction was diluted with dichloromethane (50 mL), quenched with 1.0 N NaOH (20 mL), and stirred vigorously at room temperature for 30 minutes. The layers were separated and the aqueous layer was extracted with dichloromethane (2×20 mL). The pooled organic layers were washed with (20 mL each) water and saturated brine; and dried over Na2SO4 and filtered. The filtrate was concentrated under reduced pressure to afford crude 1′-cycloheptylspiro[benzo[d][1,3]oxazine-4,4′-piperidin]-2(1H)-one as an off-white solid.

1. customquenched with 1.0 N NaOH (20 mL)
2. stirringstirred vigorously at room temperature for 30 minutes
3. customThe layers were separated
4. extractionthe aqueous layer was extracted with dichloromethane (2×20 mL)
5. washThe pooled organic layers were washed with (20 mL each) water and saturated brine
6. dry with materialand dried over Na2SO4
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure