反应详情

4-Methylene-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 601 (10.0 g, 44 mmol) was dissolved in MeOH (75 mL) at room temperature and HCl (4M in dioxane, 75 mL) was added. Stirring at room temperature was continued for 4 hours. All volatiles were removed in vacuo and a beige solid was obtained. The crude material was suspended in methylene chloride (100 mL) and N-Methyl morpholine (13.3 g, 132 mmol) was added. The mixture was cooled to 0° C. and benzyl chloroformate (8.26 g, 48.4 mmol) was added while stirring. After 30 minutes, the reaction was warmed to room temperature and the solution was washed with water and aqueous HCl (1 M). The solution was dried over sodium sulfate. Filtration and evaporation of solvents gave crude product, which was purified by silica gel chromatography (eluent:EtOAc/hexanes) to yield compound 602 (10.2 g). LCMS-ESI+: calc'd for C15H17NO4: 275.3 (M+). Found: 276.4 (M+H+).

1. customAll volatiles were removed in vacuo
2. customa beige solid was obtained
3. temperatureThe mixture was cooled to 0° C.
4. stirringwhile stirring
5. waitAfter 30 minutes
6. temperaturethe reaction was warmed to room temperature
7. washthe solution was washed with water and aqueous HCl (1 M)
8. dry with materialThe solution was dried over sodium sulfate
9. filtrationFiltration and evaporation of solvents
10. customgave crude product, which
11. customwas purified by silica gel chromatography (eluent:EtOAc/hexanes)