Irradiation of the methylpyridine N-imides (3b-g) condensed with a thiophene, furan, or pyrrole ring on the c-side of the pyridine ring gave the corresponding novel fused 1H-1, 3-(5) and/or 3H-2, 3-diazepines (6), together with the aminopyridines (7) and the parent fused pyridines (1), whereas the fused pyridine N-imide (3a) having no methyl group gave only the aminopyridine derivative (4). This photolysis may proceed by rearrangement to two kinds of diaziridine intermediates, (8) and (9) ; the latter may give the 2, 3-diazepines (6) directly by ring-expansion, whereas the former may further rearrange to the aziridine intermediate (10), followed by ring-expansion to give the 1, 3-diazepines (5). Some reactions of the diazepines (5 and 6) thus obtained were also examined.
吡啶环c侧与
噻吩、
呋喃或
吡咯环缩合的
甲基吡啶N-
酰亚胺(3b-g)在辐照下生成相应的新的7H-1,3-(5)和/或3H-2,3-二氮杂
环庚烷(6),同时生成
氨基吡啶(7)和母体缩合
吡啶(1)。无甲基的缩合
吡啶N-
酰亚胺(3a)仅生成
氨基
吡啶衍生物(4)。这种光解反应可能通过重排生成两种二
氮杂环丙烷中间体(8)和(9);后者可通过环扩张直接生成2,3-二氮杂
环庚烷(6),而前者可能进一步重排为
氮杂环丙烷中间体(10),然后通过环扩张生成1,3-二氮杂
环庚烷(5)。还考察了所得到的二氮杂
环庚烷(5和6)的一些反应。