(RS)-(4-carbamimidoyl-phenylamino)-[5-ethoxy-2-fluoro-3-(1-methyl-piperidin-4-yloxy)-phenyl]-acetic acid ethyl ester hydrochloride 、
二碳酸二叔丁酯 、
水 、
disodium;carbonate 在
乙酸乙酯 、
水 、 Brine 作用下,
以
二氯甲烷 为溶剂,
反应 2.0h,
以gave 2.3 g (RS)-[4-(tert-butoxycarbonylamino-imino-methyl)-phenylamino]-[5-ethoxy-2-fluoro-3-(1-methyl-piperidin-4-yloxy)-phenyl]-acetic acid ethyl ester as a light yellow foam的产率得到(RS)-[4-(tert-butoxycarbonylamino-imino-methyl)-phenylamino]-[5-ethoxy-2-fluoro-3-(1-methyl-piperidin-4-yloxy)-phenyl]-acetic acid ethyl ester