Nitration of 1-phenyl-4,5-dihydroimidazo- and -1,2,3-triazolo[4,5-c]pyridin-4-ones initially occurs at the para position of the phenyl ring, and the subsequent nitration yields the corresponding 7-nitro-1-(4-nitrophenyl) derivatives. Treatment of the latter with hydrazine hydrate leads to formation of 1-(4-aminophenyl)-7-methyl-4,5-dihydroimidazo- and -1,2,3-triazolo[4,5-d]pyridazin-4-ones.
[EN] 5-SUBSTITUTED PYRIDINE-2(1H)-KETONE COMPOUND AND USE THEREOF [FR] COMPOSÉ DE PYRIDINE-2(1H)-CÉTONE 5-SUBSTITUÉE ET SON UTILISATION [ZH] 5-取代的吡啶-2(1H)-酮类化合物及其应用