Studies on diazepines. XIII. Photochemical behavior of pyrazine, pyrimidine, and pyridazine N-imides.
作者:TAKASHI TSUCHIYA、JYOJI KURITA、KAZUKO TAKAYAMA
DOI:10.1248/cpb.28.2676
日期:——
Photolyses of various diazine N-ethoxycarbonylimides (3, 9, and 19), prepared from the corresponding diazines (1, 8, and 17), resulted in the formation of the pyrazole derivatives (4 and 10) from pyrazine and pyrimidine N-imides, and of the pyrrole derivatives (20) from pyridazine N-imides. These photolyses may proceed by rearrangement to diaziridine intermediates, followed by ring expansion to the corresponding 1, 2, 5-, 1, 2, 4-, or 1, 2, 3-triazepines (6, 12, or 22), which then undergo isomerization to the triaza[3.2.0]bicycloheptadienes (7, 13, and 23), followed by elimination to give the products (4, 10, and 20, respectively).
各种氮杂环 N-乙氧羧基亚胺(3、9 和 19)的光解反应,源自相应的氮杂环(1、8 和 17),导致从呀嗪和嘧啶 N-亚胺生成吡唑衍生物(4 和 10),以及从吡啶嗪 N-亚胺生成吡咯衍生物(20)。这些光解可能通过重排形成二氮环中间体,随后经过环扩张生成相应的 1,2,5-、1,2,4- 或 1,2,3-三氮唑(6、12 或 22),再经过异构化转变为三氮[3.2.0]双环七炔(7、13 和 23),最后通过消除反应生成目标产物(4、10 和 20)。