methyl 3-[(2-methylpropyl)amino]butanoate

methyl 3-[(2-phenylethyl)amino]butanoate

methyl 3-[(2-methoxyethyl)amino]butanoate

methyl 2-methyl-3-{[(pyridin-4-yl)methyl]amino}propanoate

methyl 3-{[2-(diethylamino)ethyl]amino}butanoate

methyl 3-{[2-(4-methoxyphenyl)ethyl]amino}-2-methylpropanoate

methyl 3-[(3-phenylpropyl)amino]butanoate

methyl 3-{[(4-chlorophenyl)methyl]amino}butanoate

ethyl 3-(4-methylpiperidin-1-yl)propanoate

ethyl 3-(2,6-dimethylpiperidin-1-yl)propanoate

3-[bis(2-methoxyethyl)amino]propanoic acid