The base-induced formal [4+3] cycloaddition reaction of C,N-cyclic azomethine imines with aza-ortho-quinone methides, generated in situ, is reported. This protocol provided an efficient method for the synthesis of biologically important 1,2,4-triazepine derivatives, with a wide substrate scope and excellent functional-group tolerance, and it gives moderate to excellent yields under mild conditions. Several of the derivatives exhibited in vitro antitumor activities against the A2780 cell line in a screening of the cancer cell lines HCT-116, H2228, and A2780 by an MTT assay.

中文翻译：

---

Aza-ortho-quinone Methides 与 C,​​N-Cyclic Azomethine 亚胺的 [4+3] 环加成反应合成 1,2,4-三氮杂

报告了碱诱导的正式 [4+3] 环加成反应，C,N-环状偶氮甲亚胺与氮杂邻醌甲基化物，原位生成。该协议为合成具有生物学意义的 1,2,4-三氮杂衍生物提供了一种有效的方法，具有广泛的底物范围和优异的官能团耐受性，并且在温和条件下可提供中等至优异的产率。在通过 MTT 分析筛选癌细胞系 HCT-116、H2228 和 A2780 时，几种衍生物表现出对 A2780 细胞系的体外抗肿瘤活性。