反应详情

温度

60 °C

A solution of 3-(2-(4-(6-hydroxybenzo[d]isoxazol-3-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one, prepared as described in the previous step, (6.6 g, 0.015 mmol) in DMF (50 mL) and acetone (50 mL) was treated with potassium carbonate (3.0 g, 0.03 mmol) and ethyl (2-bromoethyl)carbamate (2.4 g, 0.015 mmol). After stirring overnight at 60° C., the reaction mixture was poured in water (150 mL), extracted with chloroform (3×100 mL). The combined organic layers were dried over Na2SO4, filtered, concentrated, and purified by silica gel chromatography (elution with dichloromethane/methanol (90/10). The combined fractions were treated with HBr (150 mL, 48%) and heated to reflux for 30 min. The mixture was allowed to cool down to room temperature and made basic with ammonium hydroxide (28% NH3 in H2O) and extracted with chloroform (3×100 mL). The combined organic layers were dried over Na2SO4, filtered, concentrated, and purified by silica gel chromatography (gradient elution with dichloromethane/methanol (90/10 to 50/50) resulting in a solid which was dissolved in isopropanol (50 mL) and treated with isopropanol/HCl. The precipitate was removed by filtration and washed with iPrOH/diisopropyl ether (50/50, 3×20 mL). The precipitate was dried under vacuum to yield the title compound ESI-MS (M+1) 452. 1H NMR (360 MHz, DMSO-d6) δ ppm 1.76-1.85 (m, 1H) 1.87-1.96 (m, 1H) 2.19 (d, J=12.81 Hz, 1H) 2.37-2.48 (m, 4H) 2.98-3.10 (m, 3H) 3.10-3.28 (m, 5H) 3.37-3.46 (m, 3H) 3.72 (d, J=11.34Hz, 3H) 3.79-3.85 (m, 2H) 4.31 (t, J=4.94Hz, 1H) 7.05 (dd, J=8.78, 1.83 Hz, 1H) 7.35-7.39 (m, 1H) 8.08 (d, J=8.78 Hz, 1H).

1. extractionextracted with chloroform (3×100 mL)
2. dry with materialThe combined organic layers were dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated
5. custompurified by silica gel chromatography (
6. washelution with dichloromethane/methanol (90/10)
7. additionThe combined fractions were treated with HBr (150 mL, 48%)
8. temperatureheated
9. temperatureto reflux for 30 min
10. temperatureto cool down to room temperature
11. extractionextracted with chloroform (3×100 mL)
12. dry with materialThe combined organic layers were dried over Na2SO4
13. filtrationfiltered
14. concentrationconcentrated
15. custompurified by silica gel chromatography (
16. washgradient elution with dichloromethane/methanol (90/10 to 50/50)
17. customresulting in a solid which
18. customThe precipitate was removed by filtration
19. washwashed with iPrOH/diisopropyl ether (50/50, 3×20 mL)
20. customThe precipitate was dried under vacuum