反应详情

温度

70 °C

To a solution of diethyl 2,2-bis(hydroxymethyl)malonate (4.4 g, 20 mmol) in CH3CN (50 mL) was added Tf2O (7.1 mL, 11.85 g, 42 mmol) at −20° C., followed by two batches of DIEA (6.45 g, 50 mmol). After 0.5 hr, benzylamine (3.21 g, 35 mmol) was added at −20° C. The mixture was stirred at 70° C. for 2 hr. 100 mL of EA and 100 mL of brine were added. Organic layers were dried over Na2SO4. Purified by chromatography column on silica gel eluting with PE/EA to afford 4.8 g (82%) of diethyl 1-benzylazetidine-3,3-dicarboxylate as a yellow oil. 1H NMR (400 MHz, DMSO-d6) δ 7.29-7.34 (m, 2H), 7.22-7.27 (m, 3H), 4.17 (q, J=7.2 Hz, 4H), 3.56 (s, 2H), 3.51 (s, 4H), 2.39 (s, 3H) and 1.17 (t, J=7.2 Hz, 6H).

1. dry with materialOrganic layers were dried over Na2SO4
2. customPurified by chromatography column on silica gel eluting with PE/EA