| 71% |
Stage #1: at 20℃; for 18.00 h;
Stage #2: With sodium carbonate In methanol; water |
Mix cyclopentenone (100 g, 1.2 mol) and phthalimide (170 g, 1.2 mmol) in MeOH (900 mL) and stir for 18 h at ambient temperature. Stir vigorously with a mechanical stirrer and add 2 M aqueous Na2CO3 (80 mL). After approximately 2 h, a thick white precipitate will form. Stir at room temperature for 48 h. Collect the white solid by vacuum filtration and rinse with methanol. Suspend the solid in water (300 mL) and stir for 3 h. Collect the solid and dry in a vacuum oven at 40° C. overnight to give 195 g (71percent) of the title compound as a white solid. 1H NMR (DMSO-d6) δ 7.85-7.77 (m, 4H), 4.90 (m, 1H), 2.67 (ddd, 1H, J=18.5, 6.2, 1.3 Hz), 2.54 (dd, 1H, J=18.5, 9.2 Hz), 2.45 (m, 1H), 2.32-2.21 (m, 3H); MS (m/z): 230 (M+1, weak). |
| 71% |
With sodium carbonate In methanol; water at 20℃; for 26.00 h; |
PREPARATION 1(R,S)-2-(3-Oxo-cyclopentyl)-isoindole-1,3-dione While stirring vigorously with a mechanical stirrer, 2 M aqueous Na2CO3 (79 mL, 0.158 mol) is added to a slurry of cyclopentenone (100 g, 1.22 mol) and phthalimide (180 g, 1.22 mol) in MeOH (886 mL). After approximately 2 h, a thick white precipitate will form. The mixture is stirred at room temperature for 24 h. The white solid is collected by vacuum filtration and rinsed with methanol (1 L). The solid is suspended in water (1 L) and stirred for 3 h. The solid is collected and dried in a vacuum oven at 40° C. overnight to give 198 g (71percent) of the title compound as a white solid. 1H NMR (DMSO-d6) δ 7.85-7.77 (m, 4H), 4.90 (m, 1H), 2.67 (ddd, 1H, J=18.5, 6.2, 1.3 Hz), 2.54 (dd, 1H, J=18.5, 9.2 Hz), 2.45 (m, 1H), 2.32-2.21 (m, 3H); ES/MS m/z 230 (M+1, weak). NOTE: The product will readily undergo the retro-Michael reaction upon treatment with aqueous base. |
| 71% |
With sodium carbonate In methanol; water at 20℃; |
Preparation 1; (^^^-(S-Oxo-cyclopenty^-isoindole-ljS-dione; While stirring vigorously with a mechanical stirrer, 2 M aqueous Na2CO3 (79 mL,0.158 mol) is added to a slurry of cyclopentenone (100 g, 1.22 mol) and phthalimide (180 g, 1.22 mol) in MeOH (886 mL). After approximately 2 h, a thick white precipitate will form. The mixture is stirred at room temperature for 24 h. The white solid is collected by vacuum filtration and rinsed with methanol (1 L). The solid is suspended in water (1 L) and stirred for 3 h. The solid is collected and dried in a vacuum oven at 40 0C overnight to give 198 g (71percent) of the title compound as a white solid. IH NMR (DMSO- dβ) δ 7.85-7.77 (m, 4H), 4.90 (m, IH), 2.67 (ddd, IH, J=18.5, 6.2, 1.3 Hz), 2.54 (dd, IH, J=18.5, 9.2 Hz), 2.45 (m, IH), 2.32-2.21 (m, 3H); ES/MS m/z 230 (M+ 1, weak). NOTE: The product will readily undergo the retro-Michael reaction upon treatment with aqueous base. |