二聚反应合成氧化呋咱衍生物

采用氧化氰二聚环化的合成方法,以偕氯肟基化合物为原料,设计并合成了3,4-二苯基氧化呋咱及四种未见文献报道的化合物3,4-二(吡啶-2′-基)氧化呋咱、3,4-二(吡啶-3′-基)氧化呋咱、3,4-二(吡啶-4′-基)氧化呋咱及3,4-二(吡嗪-2′-基)氧化呋咱,利用红外光谱、核磁共振、质谱、元素分析等手段鉴定了目标化合物的结构;初步考察了不同取代基、不同催化剂、反应温度等对二聚反应合成氧化呋咱衍生物的影响。结果表明,取代基的吸电子能力越强,越有利于形成氧化氰结构,目标产物收率越高;催化剂通常选用无机弱碱(如Na2CO3、KHCO3);反应温度通常控制在2～10℃;在最佳实验条件下,目标化合物的收率分别为64.7%,71.3%,70.0%,71.1%,75.6%。

Synthesis of Furoxano Derivatives Using Dimerization Reaction

3,4-Diphenylfuroxan and four no-reported compounds 3,4-bis(pyridine-2′-yl)furoxan, 3,4-bis(pyridine-3′-yl)furoxan, 3,4-bis(pyridine-4′-yl)furoxan and 3,4-bis(pyrazine-2′-yl)furoxan were self-designed and synthesized using chloride oxime-based compounds as starting materials and the synthetic method of dimerization reaction of cyanide oxidation. The structures of target compounds were characterized by IR,NMR,MS and elemental analysis. The effects of different substituents,different catalysts,reaction temperature on the synthesis of furoxan derivatives using dimerization reaction were preliminarily investigated. Results show that the electron withdrawing ability of substituents is stronger,the structure of cyanide oxidation is more easily generated,and the yields of target products are higher. The inorganic weak base(for example Na_2CO_3,KHCO_3) is usually chosen as catalyst. The reaction temperature is usually controlled at 2-10 ℃. Under the optimal conditions, the yields of target compounds are 64.7%,71.3%,70.0%,71.1% and 75.6%,respectively.