反应详情

温度

70 °C

To a stirred solution of 31.96 g (0.092 mol) of 2a in 400 mL of anhydrous DMF was added 14.2 g (1.05 equiv.) of phthalimide and 14.4 mL (1.05 equiv.) of 1,8-diazabicyclo[5.4.0]undec-7-ene. The solution was heated at 70° C. for 18 h then concentrated in vacuo. The crude yellow oil was purified by flash chromatography using 1600 mL of silica gel and eluting with 25% EtOAc-50% EtOAc-75% EtOAc in hexane, then EtOAc, then 10% MeOH-20% MeOH in EtOAc to afford 23.8 g (80%) of 3a as an oil. Upon standing, 3a became a waxy white solid. 1H NMR (300 MHz, CDCl3) d 7.84-7.78 (m, 2H), 7.70-7.66 (m, 2H), 3.86 (t, J=5.6 Hz, 2H) 3.70 (t, J=5.6 Hz, 2H), 3.64-3.51 (m, 12H), 2.67 (bs, 1H); 13C NMR (75 MHz, CDCl3) d 168.2, 133.8, 132.0, 123.1, 72.4, 70.5, 70.4, 70.2, 70.0, 67.8, 61.6, 37.2.

1. concentrationthen concentrated in vacuo
2. customThe crude yellow oil was purified by flash chromatography
3. washeluting with 25% EtOAc-50% EtOAc-75% EtOAc in hexane