3-{[(tert-butoxy)carbonyl](propyl)amino}propanoic acid

3-{[(tert-butoxy)carbonyl][3-(diethylamino)propyl]amino}propanoic acid

3-{[(tert-butoxy)carbonyl](cyclooctyl)amino}propanoic acid

tert-butyl 3-(cyclopropylamino)propanoate

tert-butyl 3-{[2-(dimethylamino)ethyl]amino}propanoate

tert-butyl 3-{[(oxolan-2-yl)methyl]amino}propanoate

tert-butyl 3-{[(thiophen-2-yl)methyl]amino}propanoate

tert-butyl 3-[(2,2-diethoxyethyl)amino]propanoate

ethyl 3-(hexylamino)propanoate

ethyl 3-[(3-methylbutan-2-yl)amino]propanoate

ethyl 3-{[5-(diethylamino)pentan-2-yl]amino}propanoate