反应详情

Meldrum's acid (0.85 g, 5.97 mmol), DCC (1.22 g, 5.97 mmol), and DMAP (1.45 g, 11.94 mmol) were successively added to a solution of azetidine-1,3-dicarboxylic acid mono-tert-butyl ester (1.2 g, 5.97 mmol) in dichloromethane (25 mL) at room temperature. The reaction mixture was stirred overnight and then diluted by addition of cyclohexane (25 mL). The precipitate of dicyclohexyl urea was then filtered and rinsed with diethyl ether (100 mL). The mother liquors were diluted with DCM (100 mL) and washed with a 1M solution of aqueous HCl (2×30 mL), dried over sodium sulfate, filtered and concentrated to dryness. After trituration in diethyl ether the title compound was obtained as a white solid (1.9 g, 100%).

1. filtrationThe precipitate of dicyclohexyl urea was then filtered
2. washrinsed with diethyl ether (100 mL)
3. additionThe mother liquors were diluted with DCM (100 mL)
4. washwashed with a 1M solution of aqueous HCl (2×30 mL)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated to dryness