6-chloro-2-(3,4-dichlorophenyl)-3,4-dihydro-2H-pyrano[2,3-b]pyridine

2-甲氧基-3-溴-5-氯吡啶

5-氯-2-甲氧基烟醛

2,5-二氯吡啶

2-甲氧基-5-氰基吡啶