Quinolone analogues 2. A facile synthesis of novel 3-substituted 1-alkyl-4-oxo-1,4-dihydropyridazino[3,4-<i>b</i>]quinoxalines
作者:Yoshihisa Kurasawa、Kazunori Sakurai、Shinnosuke Kajiwara、Kazuho Harada、Yoshihisa Okamoto、Ho Sik Kim
DOI:10.1002/jhet.5570370538
日期:2000.9
4-dihydropyridazino[3,4-b]quinoxalin-3-yl)acetates 6a,b, respectively. On the other hand, oxidation of compounds 7a,b with N-bromosuccinimide/water furnished the 4-(1-alkyl-7-chloro-4-oxo-1,4-dihydropyridazino[3,4-b]quinoxalin-3-yl)butyric acids 8a,b, respectively. The reaction of compound 8a with hydroxylamine gave 4-(7-chloro-4-hydroxyimino-1-methyl-1,4-dihydropyridazino[3,4-b]quinoxalin-3-yl)-butyric
2-(1-烷基肼基)-6-氯喹喔啉4-氧化物1a,b与丙酮二羧酸二乙酯或1,3-环己二酮的反应得到乙基1-烷基-7-氯-3-乙氧基羰基亚甲基-1,5-二氢哒嗪[3,4- b ]喹喔啉-3-羧酸酯5a,b或6-烷基-10-氯-1-氧代1,2,3,4,6,12-六氢喹喔啉[2,3- c ] cinnolines分别如图7a,b所示。用亚硝酸氧化化合物5a,b,得到乙基1-烷基-7-氯-3-乙氧基羰基亚甲基-4-羟基-1,4-二氢吡啶并-[3,4- b ]喹喔啉-4-羧酸酯9a,b,其与碱的反应提供了乙基2-(1-烷基-7-氯-4-氧代-1,4-二氢吡啶并嗪[3,4- b[喹喔啉-3-基]乙酸盐分别为6a,b。另一方面,用N-溴代琥珀酰亚胺/水氧化化合物7a,b提供了4-(1-烷基-7-氯-4-氧代-1,4-二氢吡啶并[3,4- b ]喹喔啉-3- y)丁酸分别为8a,b。化合物8a与羟胺反应,