3-(hydroxymethyl)-4-oxido-1H-quinoxalin-4-ium-2-one

2-(甲硫基)-喹喔啉

草氨酸

二氧代琥珀酸二乙酯

3-(2-oxo-2-phenylethylidene)-3,4-dihydroquinoxalin-2(1H)-one