(R,S)-N5-[(1,1-dimethylethoxy)carbonyl]-N2-(diphenylacetyl)-ornithine 、
3-methyl-5-[2-[4-(aminomethyl)phenyl]ethyl]-1,2,4-oxadiazole-hydrochloride 在
O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate 作用下,
以49%的产率得到(R,S)-N5-[(1,1-Dimethylethoxy)carbonyl]-N2-(diphenylacetyl)-N-[[4-[2-(3-methyl-1,2,4-oxadiazol-5-yl)ethyl]-phenyl]methyl]-ornithinamide