反应详情

Following the procedure of step (iv) of Example 1 but using a 300-ml portion of the o-xylene solution of butyl α-acetamidocinnamate as obtained in step (iii) of Example 8 in place of the o-xylene solution of methyl α-acetamidocinnamate, the hydrogenation reaction was carried out in the same manner as in said step (iv) of Example 1. The conversion of butyl α-acetamidocinnamate was 100 percent and the selectivity toward N-acetyl-DL-phenylalanine butyl ester 99 mole percent. The palladium-on-carbon catalyst was filtered off from the reaction mixture, the filtrate was concentrated under reduced pressure and the residue was purified by column chromatography to give 32 g of N-acetyl-DL-phenylalanine butyl ester.