反应详情

温度

-78 °C

N,N-diisopropylamine (4.40 mL, 31.3 mmoles) was dissolved in tetrahydrofuran (50 mL). The mixture was cooled to −78° C. Butyllithium (2.5 M in hexanes, 12.4 mL, 31 mmoles) was added dropwise to the stirred solution. After stirring at −78° C. for 30 min, a solution of tert-butyl 4-(2-methoxy-2-oxoethyl)piperidine-1-carboxylate (6.65 g, 25.8 mmoles) in tetrahydrofuran (15 mL) was added dropwise to the mixture. Stirring was continued at −78° C. for 1 h. A solution of 2-nitrobenzaldehyde (3.90 g, 25.8 mmoles) in tetrahydrofuran (20 mL) was then added to the mixture dropwise, and then stirring was continued at −78° C. for a further 2.5 h. The reaction was quenched with cold aqueous ammonium chloride and then diluted with water. The mixture was extracted twice with ethyl acetate and the aqueous phase was discarded. The material was dried (magnesium sulfate) filtered, and concentrated to dryness. Silica gel chromatography afforded the desired product in 94% yield as light yellow foam. MS m/e (M-C4H8+H)+=353.1.

1. stirringStirring
2. waitwas continued at −78° C. for 1 h
3. stirringstirring
4. waitwas continued at −78° C. for a further 2.5 h
5. customThe reaction was quenched with cold aqueous ammonium chloride
6. additiondiluted with water
7. extractionThe mixture was extracted twice with ethyl acetate
8. dry with materialThe material was dried (magnesium sulfate)
9. filtrationfiltered
10. concentrationconcentrated to dryness