反应详情

温度

0 °C

Tert-butyl 2,7-diazaspiro[3.5]nonane-2-carboxylate (21.0 g, 92.8 mmol) and triethylamine (20 mL, 186 mmol) were dissolved in dichloromethane (200 mL). The reaction was cooled to 0° C. and a solution of benzyl 2,5-dioxopyrrolidin-1-yl carbonate (23.1 g, 92.8 mmol) in dichloromethane (25 mL) was added dropwise. The ice-bath was removed and the reaction was stirred at room temperature for 6 hours. The reaction was diluted with dichloromethane (100 mL), washed with 10% aqueous citric acid solution (100 mL), water (100 mL) and brine (100 mL). The organic solution was dried over MgSO4, filtered and concentrated to afford 7-benzyl 2-tert-butyl 2,7-diazaspiro[3.5]nonane-2,7-dicarboxylate (33.5 g, 100%) as colorless oil, which was used in the next step without further purification.

1. customThe ice-bath was removed
2. additionThe reaction was diluted with dichloromethane (100 mL)
3. washwashed with 10% aqueous citric acid solution (100 mL), water (100 mL) and brine (100 mL)
4. dry with materialThe organic solution was dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated