4-hydroxy-6-(pyridin-2-yl)-4,5-dihydropyridazin-3(2H)-one

methyl 4-oxo-4-(2-pyridyl)butanoate

2-乙酰基吡啶

2-hydroxy-4-oxo-4-(pyridin-2-yl)butanoic acid

乙醛酸