反应详情

温度

25 °C

A 50° C. suspension of Example 3A (1.65 g) in 1:1 THF/ethanol (34 mL) was treated with hydrazine monohydrate (3×240 μL) at 1 hour intervals. One hour after the final addition the mixture was cooled to 25° C. and filtered. The filtrate was concentrated in vacuo. The resultant material was dissolved in a mixture of pyridine (17 mL) and dichloromethane (17 mL), cooled to −5° C., and treated with acetic anhydride (854 μL). The reaction mixture was warmed to room temperature, stirred for 5 minutes, and concentrated to provide crude product. The crude product was dissolved in 4:1 THF/dichloromethane (75 mL) and washed with 1:1 brine/water. The aqueous wash was extracted with dichloromethane (25 mL), and the combined extracts were dried over MgSO4. Next the mixture was filtered and concentrated. The residue was dissolved in acetone (20 mL) and filtered. The filtrate was concentrated and the residue triturated with hexanes to provide the desired product. MS (ESI(+)) m/e 277 (M+H)+; 1H NMR (300 MHz, CDCl3) δ 7.5-7.4 (m, 2H), 7.16-7.19 (dd, J=2.4, 8.4 Hz, 1H), 5.93 (bt, 1H), 4.8 (m, 1H), 4.05 (t, J=9 Hz, 1H), 3.8-3.6 (m, 3H), 3.28 (s, 1H), 2.02 (s, 3H).

1. additionOne hour after the final addition the mixture
2. filtrationfiltered
3. concentrationThe filtrate was concentrated in vacuo
4. dissolutionThe resultant material was dissolved in a mixture of pyridine (17 mL) and dichloromethane (17 mL)
5. temperaturecooled to −5° C.
6. additiontreated with acetic anhydride (854 μL)
7. temperatureThe reaction mixture was warmed to room temperature
8. concentrationconcentrated
9. customto provide crude product
10. washwashed with 1:1 brine/water
11. washThe aqueous wash
12. extractionwas extracted with dichloromethane (25 mL)
13. dry with materialthe combined extracts were dried over MgSO4
14. filtrationNext the mixture was filtered
15. concentrationconcentrated
16. dissolutionThe residue was dissolved in acetone (20 mL)
17. filtrationfiltered
18. concentrationThe filtrate was concentrated
19. customthe residue triturated with hexanes