反应详情

To a stirred solution of 1-(2-propenyl)-2-piperazinone hydrochloride (7.9 g, 44 mmol) and diisopropylethylamine (8 mL, 46 mmol) in dichloromethane (100 mL) was added 2-propylisocyanate (5.6 g, 66 mmol). The mixture was stirred at ambient temperature for 18 h. Water (75 mL) was added, and the organic layer was collected, dried (MgSO4), filtered. The solvent was removed in vacuo and the residue was purified by silica gel column chromatography using a gradient elution of 2%, 3%, 4% MeOH in CH2Cl2. Product-containing fractions were combined and concentrated in vacuo to yield 1-(2-propenyl)-4-(N-2-propylcarbamoyl)-2-piperazinone as a solid. HPLC RT=2.17 min (Mehtos A); ES MS (M+H)=226; 1H NMR (400 MHz, CDCl3) δ 5.75 (ddt, 1H), 5.2 (overlapping doublets, 2H), 4.32 (b rd, 1H), 4.04 (d, J=6 Hz, 2H), 3.97 (s, 2H), 3.67 (t, J=7 Hz, 2H), 3.33 (t, J=7 hz, 2H), 1.16 (d, J=7 Hz, 6H).

1. customthe organic layer was collected
2. dry with materialdried (MgSO4)
3. filtrationfiltered
4. customThe solvent was removed in vacuo
5. customthe residue was purified by silica gel column chromatography
6. washa gradient elution of 2%, 3%, 4% MeOH in CH2Cl2
7. concentrationconcentrated in vacuo