2-bis(tert-butoxycarbonylmethyl)aminopentanedioic acid 1-tert-butyl ester 、 14-(2-aminoethyl)-6,7,9,10,13,14,15,16,18,19,21,22-dodecahydro-12H-5,8,11,17,20,23-hexaoxa-14-aza-benzocycloheneicosene-2,3-dicarboxylic acid dimethyl ester dihydrochloride 在
1-羟基苯并三唑 、
N,N-二异丙基乙胺 、
N,N'-二环己基碳二亚胺 作用下,
以
氯仿 为溶剂,
以60%的产率得到14-{2-[4-(bis-tert-butoxycarbonylmethyl-amino)-4-tert-butoxycarbonyl-butyryl-amino]-ethyl}-6,7,9,10,13,14,15,16,18,19,21,22-dodecahydro-12H-5,8,11,17,20,23-hexaoxa-14-azabenzocyclohenicosene-2,3-dicarboxylic acid dimethyl ester