methyl 4-{[2-(2-naphthylsulfonyl)-1-(1-piperidinylcarbonyl)hydrazino]methyl}-1-piperidinecarboxylate

methyl 4-{[2-(tert-butoxycarbonyl)-1-(1-piperidinylcarbonyl)hydrazino]methyl}-1-piperidinecarboxylate

N,N'-bis-Boc-S-methyl-isothiourea

N'-(1-piperidinylcarbonyl)-N'-(4-piperidinylmethyl)-2-naphthalenesulfonohydrazide

methyl 4-{[1-(1-piperidinylcarbonyl)hydrazino]methyl}-1-piperidinecarboxylate