Dicyclohexylcarbodiimide → N-benzyloxy-3-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-N-(2,4,6-trimethoxybenzyl)-propanamide

関与物質

反応条件

反応手順

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).

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