6-Chlor-2-methyl-3 , 1-benzoxazin-4-one ( 1 ) was prepared by acylated cyclization of 6-chlor-anthranilic acid with acetic oxide. 3-Amino-6-chlor-2-methyl-4(3H)-quinazolinone (2) was ob-tained by refluxing reaction of 1 in 80% N2 H4 ·H2 O. Four novel 6-chlor-4(3H)-quinazolinone Schiff bases(4a~4d) were synthesized by the reaction of 2 with hydroxyl arylamine. The structures were characterized by 1 H NMR, 13 C NMR, IR and elementary analysis. The preliminary antibacterial activi-ties of 4a~4d against Staphylococcus aureus(A), Escherichia coli(B) and Bacillus subtilis(C) were investigated by agar diffusion method. The results showed that 4 a~4 d exhibited certain antibacterial activities with drug concentration of 300 mg·mL-1and 6-chlor-2-methyl-3-[(5-methyl-2-hydroxyphe-nyl) methylene amimo]-4(3H)-quinazolinone(4c) was the best, which possessed 8. 8 mm, 11. 9 mm and 9. 6 mm inbibition zone diameters against A~C, respectively.%以6-氯邻氨基苯甲酸为起始原料,与醋酐酰化关环制得6-氯-2-甲基噁嗪-4-酮(1);1在80%水合肼中回流反应制得6-氯-2-甲基-3-氨基-4(3H)-喹唑啉酮(2);2与羟基芳醛反应合成了4种新型的6-氯-4(3H)-喹唑啉酮类Schiff碱(4a~4d),其结构经1H NMR,13C NMR,IR和元素分析表征.采用琼脂扩散法研究了4a~4d对金黄色葡萄球菌(A)、大肠杆菌(B)和枯草杆菌(C)的抑制活性.结果表明:用药浓度为300 mg·mL-1时,4a~4d对A~C均有一定的抑制活性,其中6-氯-2-甲基-3-(5-甲基-2-羟基苯亚甲氨基)-4(3H)-喹唑啉酮(4c)抑菌活性最强,对A~C的抑菌圈直径分别为8.8 mm,11.9 mm和9.6 mm.
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