2,5-二氢-4-羟基-5-氧代-1-苯基-1H-吡咯-3-羧酸乙酯

ethyl 3-(N-(3-ethoxy-3-oxopropyl)anilino)propanoate

1-苯基氮杂啶-2-酮

ethyl 4,5-dioxo-1-phenylpyrrolidine-3-carboxylate