5-氧代氮杂烷-1,4-二羧酸二乙酯

(4-甲氧基苯氧基)乙酸乙酯

Methyl-ethoxycarbonylmethyl-<2-ethoxycarbonyl-ethyl>-amin

ethyl (N-ethyl-N-phenylamino)acetate

diethyl fumarate