新型喹唑啉-4(3H)-酮Schiff碱的合成及生物活性

为探索具有高杀菌活性的新型喹唑啉酮类先导化合物,以4-氯-2-氨基苯甲酸为起始原料,经重氮化、叠氮化、酯化等系列反应,得到17个未见文献报道的喹唑啉-4(3H)-酮Schiff碱类化合物。所有目标化合物的结构均经IR、1H NMR、MS及元素分析确证。初步生物活性测定结果表明,目标化合物表现出一定的杀菌活性,特别是对芒果褐色蒂腐病菌Phomopsis mangiferae Ahmad活性较好。化合物7-氯-3-(2,4-二氯-苯基)亚氨乙基-2-苯氨基喹唑啉-4(3H)-酮 (7e) 在 100 μg/mL 时,对橡胶棒孢霉叶斑病菌Corynespora cassiicola Wei和芒果褐色蒂腐病菌Phomopsis mangiferae Ahmad的抑制率分别为26.21%±1.11%和98.18%±1.07%,与对照药剂百菌清(25.64%±1.31%和100%)相当。初步的构效关系表明,吸电子基团有利于提高目标化合物的杀菌活性。

Synthesis and fungicidal activity of novel 4(3H)-quinazolinone Schiff base derivatives

A series of novel 4(3H)-quinazolinone Schiff base derivatives were synthesized using 2-amino-4-chlorobenzoic acid as the starting material. The structures of the resultant compounds were characterized by IR,1H NMR, MS and elementary analyses. The preliminary bioassay data showed that the final compounds exhibited fungicidal activities with different levels. Phomopsis mangiferae Ahmad were sensitive to most of the compounds. In particular, 7e showed potential antifungal activity against Corynespora cassiicola Wei and Phomopsis mangiferae Ahmad with the inhibition rates of 26.21%±1.11% and 98.18%±1.07%, respectively, which were equal to those of the fungicide chlorothalonil (25.64%±1.31% and 100%, respectively) at the concentration of 100 μg/mL. The preliminary Structure Activity Relationships (SAR) revealed that electron-withdrawing groups were favorable for improving antifungal activities of the title compounds.