反应详情

温度

-78 °C

To a solution of 28 (7.3 mmol) in THF was added 1.6 N butyllithium/hexane solution (7 ml) at −78° C. under N2 atmosphere. The solution was stirred at −78° C. for 1 hour and a solution of tert-butyl 4-(methoxy(methyl)carbamoyl)piperidine-1-carboxylate (1 g, 3.6 mmol) in THF was added. The solution was maintained at −78° C. for 4 hour, and then quenched with sat. aqueous NH4Cl and allowed to warm to rt with stirring. The organic layer was separated and then the aqueous layer was extracted with ethyl acetate. The combine extract was washed with water, dried over Na2SO4, filtered, concentrated, and the residue chromatographed on silica eluted with an ethyl acetate-hexane (1:4, v/v) and the aimed product was obtained. The yield was 40%. NMR (CDCl3): δ 1.47 (s, 9H), 1.62-1.70 (m, 4H), 2.83 (s, 2H), 3.64-3.73 (m, 1H), 4.17 (br, 2H), 4.25-4.36 (m, 2H), 4.68-4.87 (m, 2H), 7.23-7.26 (m, 1H), 7.38-7.40 (m, 1H), 8.25-8.30 (m, 1H).

1. temperatureThe solution was maintained at −78° C. for 4 hour
2. customquenched with sat. aqueous NH4Cl
3. temperatureto warm to rt
4. stirringwith stirring
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with ethyl acetate
7. extractionThe combine extract
8. washwas washed with water
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated
12. customthe residue chromatographed on silica
13. washeluted with an ethyl acetate-hexane (1:4, v/v)