1-[3-(2-methylpropyl)-1,2,4-thiadiazol-5-yl]piperazine

3-{[(tert-butoxy)carbonyl](1-phenylethyl)amino}propanoic acid

3-{[(tert-butoxy)carbonyl](2-methoxyethyl)amino}propanoic acid

3-{[(tert-butoxy)carbonyl](2,2-dimethoxyethyl)amino}propanoic acid

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

3-((tert-butoxycarbonyl)(4-phenylbutan-2-yl)amino)propanoic acid

3-{[(tert-butoxy)carbonyl][2-(1H-indol-3-yl)ethyl]amino}propanoic acid

tert-butyl 3-[(pentan-3-yl)amino]propanoate

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

tert-butyl 3-{[2-(pyrrolidin-1-yl)ethyl]amino}propanoate

tert-butyl 3-{[2-(piperidin-1-yl)ethyl]amino}propanoate