HCC-CH2-NH-CO-CH2-O-(CH2-CH2O)2-CH2-COOH 、
4-((S)-2-((S)-2-aminopropanamido)-5-ureidopentanamido)benzyl (2-(((((S)-4-ethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methylene)amino)oxy)ethyl)carbamate 2,2,2-trifluoroacetate 在
N,N'-二环己基碳二亚胺 作用下,
以63.5%的产率得到4-((2S,5S)-5-methyl-4,7,17-trioxo-2-(3-ureidopropyl)-9,12,15-trioxa-3,6,18-triazahenicos-20-ynamido)benzyl (2-(((((S)-4-ethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-11-yl)methylene)amino)oxy)ethyl)carbamate