(E)-3-(4-hydroxy-3-methoxy-5-nitrophenyl)prop-2-enoic acid

diethyl 2-[2-(dimethylamino)ethyl]propanedioate

3-pyridin-2-ylprop-2-enoic acid

N,N-二甲基-2-亚甲基-beta-丙氨酸

β,β'-bis-dimethylamino-isobutyric acid