2-methylpyrazino[1,2-a]indole-1,3,4-trione

ethyl 2-oxo-2-(pyrazin-2-ylmethylamino)acetate

3,4-二甲氧基苯基乙醛酸乙酯

ethyl 2-(cyclohexylamino)-2-oxoacetate

4-二甲基氨基苯甲酰基甲酸乙酯