Substituted Quinolinones. Part 27. Regioselective Heterocyclization of Some Diazolo- and/or Triazepino[b or c]quinoline Derivatives

Reactivity of 3-acetyl-4-methylthioquinolin-2(1H)-one (1) towards 1,2- and/or 1,4-diazanucleophiles has been studied under different reaction conditions. Condensation of key compound 1 with hydrazine, phenylhydrazine, hydroxylamine hydrochloride, semicarbazide and thiosemicarbazide was carried out in different media. It was found that the nature of products is extremely dependent on both reactivity of the reagent and the ambient conditions. Accordingly, the reaction regioselectivety led to different [1,2]diazolo and or [1,2,4]triazepino[b or c]quinoline derivatives in addition to open chain condensates which were transformed to either annellated heterocyclo[b or c] quinolines, in good yields. The structure of new products was established on basis of their analytical and spectral data.