反应详情

The acid 14 (4.5 g, 21 mmol) was refluxed in 60 mL of (Ac)2O with NaOAc (1.72 g, 21 mmol) for 3 h. After cooling, the reaction mixture was concentrated. The residue was dissolved in EtOAc, washed with brine, dried over MgSO4, filtered and evaporated to give a deep red oil that was purified by silica gel column chromatography (CHCl3:MeOH/99:1). The maleimide product 15 was isolated as a white solid (1.4 g, 32%). 1H NMR (DMSO-d6): δ 1.18-1.24 (2H, m), 1.45-1.52 (4H, m), 2.18 (2H, t, J=7.5), 3.38 (2H, t, J=7.0), 7.01 (2H, s).

1. temperatureAfter cooling
2. concentrationthe reaction mixture was concentrated
3. dissolutionThe residue was dissolved in EtOAc
4. washwashed with brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customto give a deep red oil that
9. customwas purified by silica gel column chromatography (CHCl3:MeOH/99:1)