Abstract
The reaction of 6-chloro-2-hydrazinoquinoxaline 4-oxide (11) with ethyl chloroglyoxylate provided ethyl 8-chloro-4H-1,3,4-oxadiazino[5,6-b]quinoxaline-2-carboxylate (12) through the intramolecular cyclization. The reaction of 12 with hydrazine hydrate afforded the $C_2$-hydrazinocarbonyl derivative 13, whose reactions with substituted benzaldehydes or heteroaryl aldehydes provided 8-chloro-2-(substituted benzylidenehydrazinocarbonyl)-4H-1,3,4-oxadiazino[5,6-b]quinoxalines (14) or 8-chloro-2-[(2-substituted methylidene)hydrazinocarbonyl]-4H-1,3,4-oxadiazino[5,6-b]quinoxalines(15), respectively.
6-Chloro-2-hydrazinoquinoxaline 4-oxide(11)와 ethyl chloroglyoxylate를 반응시켜 분자내 고리화반응에 의한 ethyl 8-chloro-4H-1,3,4-oxadiazino[5,6-b]quinoxaline-2-carboxylate(12)를 합성하였다. 화합물 12를 hydrazine hydrate와 반응시켜 $C_2$-hydrazinocarbonyl 유도체 13이 합성되었는데, 이것을 치환 벤즈알데히드류 및 헤테로아릴 알데히드류와 반응시켜 8-chloro-2-(substituted benzylidenehydrazinocarbonyl)-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(14) 및 8-chloro-2-[(2-substituted methylidene)hydrazinocarbonyl]-4H-1,3,4-oxadiazino[5,6-b]quinoxaline류(15)를 각각 합성하였다.