反应详情

A solution of 2-acetylamino-3-(4-hydroxy-phenyl)-propionic acid 20 (13.4 grams, 60.09 mmol) and 2-amino-3-(4-hydroxy-phenyl)-propionic acid methyl ester 1 (11.7 grams, 60.00 mmol) in anhydrous dichloro methane (100 mL) under a nitrogen atmosphere at 0° C. is added dropwise to a solution of 1,3-dicyclohexyl carbodiimide (31 grams, 150.24 mmol) in dichloro methane (75 mL). The mixture is stirred at room temperature for 6 hours. The resulting solids are filtered off. The organic phase is washed with 5% sodium bicarbonate (2×25 mL) and water (2×25 mL), dried over sodium sulphate, and distilled to give crude 21, which can be purified in appropriate solvent.

1. filtrationThe resulting solids are filtered off
2. washThe organic phase is washed with 5% sodium bicarbonate (2×25 mL) and water (2×25 mL)
3. dry with materialdried over sodium sulphate
4. distillationdistilled
5. customto give crude 21, which
6. customcan be purified in appropriate solvent