benzyl 4-[1-(2-chloro-pyridin-3-yl)-ureido]-piperidine-1-carboxylate

ethyl 4-((2-nitropyridin-3-yl)amino)piperidine-1-carboxylate

4-氨基-1-哌啶甲酸乙酯

N-叔丁氧羰基-4-哌啶酮

2,3-二氨基吡啶