methyl 3-{[2-(piperidin-1-yl)ethyl]amino}butanoate

methyl 3-[(3-methoxypropyl)amino]-2-methylpropanoate

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

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

methyl 3-{[3-(dimethylamino)propyl]amino}butanoate

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

methyl 3-{[(2-chlorophenyl)methyl]amino}-2-methylpropanoate

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

methyl 3-(tert-butylamino)-2-methylpropanoate

methyl 3-(cyclooctylamino)-2-methylpropanoate

ethyl 3-[bis(2-methylpropyl)amino]propanoate