Generation of oxodiazonium ions 3. Synthesis of [1,2,5]oxadiazolo[3,4-c]cinnoline-1,5-dioxides
作者:V. P. Zelenov、A. A. Voronin、A. M. Churakov、M. S. Klenov、Yu. A. Strelenko、V. A. Tartakovsky
DOI:10.1007/s11172-011-0311-8
日期:2011.10
A reaction of 4-(N-nitramino)-3-phenylfuroxane with the Ac2O/H2SO4 system leads to the formation of [1,2,5]oxadiazolo[3,4-c]cinnoline-1,5-dioxide, the first representative of furoxanocinnolines. The reaction presumably proceeds through the transformation of the nitramine fragment NHNO2 to the oxodiazonium ion [N=N=O]+ with subsequent intramolecular attack by this cation on the phenyl ring. Furoxanocinnoline is also formed in the reaction of the 4-(N-nitramino)-3-phenylfuroxane O-methyl derivative with H2SO4. It is assumed that this reaction also proceeds with involvement of the intermediate cation [N=N=O]+ formed by the protonation of the N=N(O)OMe group and subsequent elimination of MeOH. 7-Nitro derivative is formed when furoxanocinnoline is nitrated with the concentrated HNO3/H2SO4 mixture. The compounds obtained were characterized by 1H, 13C, and 14N NMR spectroscopy.
4-(N-nitramino)-3-phenylfuroxane 与 Ac2O/H2SO4 系统发生反应,生成 [1,2,5]恶二唑并[3,4-c]噌啉-1,5-二氧化物,这是呋喃并噌啉类化合物的第一个代表。该反应可能是通过硝胺片段 NHNO2 转化为噁二唑离子 [N=N=O]+ 并随后由该阳离子对苯环进行分子内攻击而进行的。4-(N-nitramino)-3-phenylfuroxane O-methyl 衍生物与 H2SO4 反应也会生成呋喃噌啉。据推测,这一反应也是在 N=N(O)OMe 基团质子化形成的中间阳离子 [N=N=O]+ 的参与下进行的,随后 MeOH 被消除。用浓 HNO3/H2SO4 混合物硝化呋喃并噌啉会生成 7-硝基衍生物。获得的化合物通过 1H、13C 和 14N NMR 光谱进行表征。