3(S)-(Pyridin-3-yl)-3-(5-(5,6,7,8-tetrahydro-[1,8]naphthyridin-2-yl)-pentanoylamino)propionic acid ethyl ester 、
sodium hydroxide 在
silica gel 、 EtOAc EtOH H2O NH4OH 作用下,
以
乙醇 为溶剂,
反应 2.0h,
以to give 1-9 as a white solid的产率得到3(S)-(Pyridin-3-yl)-3-(5-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)-pentanoylamino)-propionic acid