反应详情

温度

0 °C

To a solution of 3-[benzyloxy(2,4,6-trimethoxybenzyl)amino]-3-oxopropanoic acid (9.41 g, 24.16 mmol), Meldrum's acid (3.84 g, 26.58 mmol), and DMAP (3.54 g, 29.0 mmol) in dichloromethane (125 mL) was dropwise added a solution of DCC (5.5 g, 26.6 mmol) in dichloromethane (25 mL) via addition funnel over a period of 1 h at 0° C. The mixture was left in the refrigerator overnight. DCU was filtered off and the filtrate was washed with 5% KHSO4 (3 times) and brine and dried over MgSO4 for 4 h in the refrigerator. The drying agent was removed by filtration and acetic acid (16 mL) was added to the filtrate. The mixture was again cooled at 0° C. and sodium borohydride (2.3 g, 60.4 mmol) was added in small portions while stirring over 1 h. The reaction mixture was left overnight in the refrigerator. The next day, the solution was washed 3 times with brine and 2 times with water. The organic layer was concentrated in vacuo and the crude material was recrystallized from EtOAc-hexanes mixture to give 8.08 g of N-benzyloxy-3-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-N-(2,4,6-trimethoxybenzyl)-propanamide as a white solid (67% yield).

1. additionvia addition funnel over a period of 1 h at 0° C
2. filtrationDCU was filtered off
3. washthe filtrate was washed with 5% KHSO4 (3 times) and brine
4. dry with materialdried over MgSO4 for 4 h in the refrigerator
5. customThe drying agent was removed by filtration and acetic acid (16 mL)
6. additionwas added to the filtrate
7. waitThe reaction mixture was left overnight in the refrigerator
8. washThe next day, the solution was washed 3 times with brine and 2 times with water
9. concentrationThe organic layer was concentrated in vacuo
10. customthe crude material was recrystallized from EtOAc-hexanes mixture