3-苄基-5-(1-(2-氧代-1-氧杂螺[4,5]癸-3-烯-3-基)亚乙基)-2-氨基咪唑啉-4-酮类化合物的合成及杀菌活性

Synthesis and fungicidal activity of 3-benzyl-5-(1-(2-oxo-1-oxaspiro[4,5]dec-3-en-3-yl)ethylidene)-2-aminoimidazolin-4-one derivatives

为寻找高活性的杀菌化合物,在前期合成5-(1-(4-甲基-2-氧代-1-氧杂螺[4,5]癸-3-烯-3-基)亚乙基)-2-氨基咪唑啉-4-酮类化合物的基础上进行结构修饰,在咪唑啉-4-酮的3-位引入苄基,设计并合成了一系列未见文献报道的化合物,其结构经过核磁共振氢谱(1H NMR)、碳谱(13C NMR)及高分辨质谱(HR-ESI-MS)确证。经高效液相色谱(HPLC)分析显示,Z-构型中间体化合物6在酸性条件下会发生氮质子化开环再环化,转化为E-构型化合物7。离体杀菌活性测定结果表明,3-位苄基的引入改善了该类化合物的杀菌活性,其中化合物(E)-3-苄基-5-(1-(4-甲基-2-氧代-1-氧杂螺[4,5]癸-3-烯-3-基)亚乙基)-2-(4-甲氧基苯基)氨基-咪唑啉-4-酮(9c)和(E)-3-苄基-5-(1-(4-甲基-2-氧代-1-氧杂螺[4,5]癸-3-烯-3-基)亚乙基)-2-(4-氟苯基)氨基-咪唑啉-4-酮(9h)对油菜菌核病菌的EC50值分别为14.3和21.1 mg/L。活体杀菌活性测试结果显示,在400 mg/L下化合物9c对于黄瓜霜霉病和小麦白粉病的防治效果分别为80%和85%。

In order to discover novel compounds with high fungicidal activities,a series of novel compounds were designed and synthesized based on the structural modification of 5-(1-(4-methyl-2-oxo-1-oxaspiro[4,5]dec-3-en-3-yl)ethylidene)-2-aminoimidazolin-4-one derivatives,and introduction of a benzyl group at the 3-position of imidazolinone.Their structures were characterized by 1H NMR,13C NMR and HR-ESI-MS spectral data.Furthermore,these results of HPLC analysis verified that the Z-configuration of compound 6 would be reversed to the E-configuration of 7 through nitrogen protonation,ring opening,and ring reclosing processes under acidic conditions.The preliminary in vitro evaluation results showed that the introduction of the 3-benzyl group significantly improved the fungicidal activity of this type of compounds,and the EC50 value of 3-benzyl-5-(1-(4-methyl-2-oxo-1-oxaspiro[4,5]dec-3-en-3-yl)ethylidene)-2-(4-methoxy-phenylamino)-imidazolin-4-one(9c)and 3-benzyl-5-(1-(4-methyl-2-oxo-1-oxaspiro[4,5]dec-3-en-3-yl)ethylidene)-2-(4-fluorophenylamino)-imidazolin-4-one(9h)against Sclerotinia sclerotiorum were 14.3 and 21.1 mg/L,respectively.In the in vivo evaluation,the efficacies of compounds 9c were 80%and 85%against cucumber downy mildew and wheat powery mildew at a concentration of 400 mg/L,respectively.