反应详情

2.69 g (8.0 mmol) of methyl benzyloxycarbonyl-L-valyl-L-alaninate [E. Klieger and E. Schr{overscore (o)}der: Ann. Chem. 661, 193 (1963)] are dissolved in 25 ml of methanol, 0.72 9 (8.0 mmol) of anhydrous oxalic acid and 0.1 g of Pd/C catalyst are added, then the mixture is submitted to hydrogenation at about 20° C. The catalyst is filtered off and the filtrate is evaporated at a pressure of 2.0-2.5 kPa. The crystalline residue is rubbed with diethyl ether, filtered, washed with diethyl ether and dried in a vacuum desiccator.

1. customis submitted to hydrogenation at about 20° C
2. filtrationThe catalyst is filtered off
3. customthe filtrate is evaporated at a pressure of 2.0-2.5 kPa
4. filtrationfiltered
5. washwashed with diethyl ether
6. customdried in a vacuum desiccator