Condensed and bonded quinoxalines

2-Chloro-3-formylquinoxaline was synthesized from 2-chloro-3-methylquinoxaline by the Kröhnke method, and the properties of its phenylhydrazone were studied. It was found that 2-Y-3-formylquinoxalines display an anomalously low reactivity as compared with 2-Y-benzoylquinoxalines (Y=H, OH, Cl) in the synthesis of pyrazolo[3,4-b]quinoxalines.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 852–856, June, 1973.