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

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

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

tert-butyl 3-{[2-(4-methoxyphenyl)ethyl]amino}propanoate

tert-butyl 3-[(3-phenylpropyl)amino]propanoate

tert-butyl 3-[(diphenylmethyl)amino]propanoate

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

tert-butyl 3-(cycloheptylamino)propanoate

ethyl 3-{[3-(morpholin-4-yl)propyl]amino}propanoate

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

ethyl 3-{[(2H-1,3-benzodioxol-5-yl)methyl]amino}propanoate