ethyl 5-(4-benzoylpiperazin-1-yl)pentanoate

5-[(2-oxo-1H-quinolin-6-yl)oxy]pentanoic acid

ethyl 5-(4-acetylphenyl)pentanoate

ethyl 5-[[methyl(phenylmethoxycarbonyl)amino]-phenylmethoxycarbonylamino]pentanoate

benzyl N-methyl-N-[[5-oxo-5-(propan-2-ylamino)pentyl]-phenylmethoxycarbonylamino]carbamate