n-butyl 4-[[2-oxo-4-(piperidin-4-yl)-piperazin-1-yl]acetyl]phenoxyacetate dihydrochloride 、
(5-甲基-2-氧代-1,3-二氧杂环戊烯-4-基)甲基 4-硝基苯基碳酸酯 以89.3 mg (86.7%)的产率得到n-Butyl 4-[[4-[(5-Methyl-2-oxo-1,3-dioxol-4-yl)methyloxycarbonylpiperidin-4-yl]-2-oxopiperazin-1-yl]acetyl]phenoxyacetate