、
5-(benzyloxycarbonylamidino)-2-benzofurancarboxylic acid 、
ethyl (S)-3-(4-aminophenyl)-2-(trifluoromethylsulfonylamino)propionate 在
silica gel 、
ethyl acetate n-hexane 作用下,
以to give 1.31 g of ethyl (S)-3-[4-[(5-(benzyloxycarbonylamidino)-2-benzofuranyl]carbonylamino)phenyl]-2-(trifluoromethylsulfonylamino)propionate as a colorless solid (65%)的产率得到ethyl (S)-3-[4-[[5-(benzyloxycarbonylamidino)-2-benzofuranyl]carbonylamino]phenyl]-2-(trifluoromethylsulfonylamino)propionate