A series of 3-Substituted amino-4,5-tetramethylene thieno[2,3-d] [1,2,3]-triazine-4(3H)-ones have been synthesized and characterized by UV,IR, 1H NMR, elemental and mass spectral analysis. The title compounds were evaluated for their antimicrobial activity by agar diffusion method against four bacteria and three fungi using Ampicillin and Miconazole nitrate as standards. The compounds VIIIa, IXa, Xa and XIa showed an antimicrobial efficacy considerably greater than the compounds Ia to VIIa with –H, phenyl and electron donating (activating) groups like methyl, ethyl and tolyl substitutions at R, suggesting that lipophillic groups like chloro, fluoro substitution on the phenyl ring plays an important role in enhancing the antimicrobial properties of this class of compounds.

From the screening results it can be concluded that the compounds having the lipophillic groups like chlorophenyl and fluorophenyl groups at R exhibited appreciable antimicrobial activities. Whereas, the compounds are having –H, phenyl and electron donating (activating) groups like methyl, ethyl and tolyl substituents at R were less active against all the organisms used.

合成了一系列3-取代的氨基-4,5-四亚甲基噻吩并[2,3- d ] [1,2,3]-三嗪-4（3 H）-并通过UV，IR，1H NMR表征，元素和质谱分析。以氨苄青霉素和硝酸咪康唑为标准，通过琼脂扩散法评价了标题化合物对四种细菌和三种真菌的抗菌活性。化合物VIIIa，IXa，Xa和XIa的抗菌功效远大于化合物Ia到VIIa在R处带有–H，苯基和给电子（活化）基团（如甲基，乙基和甲苯基）的化合物，表明苯环上的亲油基团（如氯，氟取代基）在增强此类化合物的抗菌性能方面起着重要作用。

从筛选结果可以得出结论，在R处具有亲脂基团如氯苯基和氟苯基的化合物表现出明显的抗微生物活性。而，这些化合物是具有-H，苯基和供电子（激活），如在甲基，乙基和甲苯基取代基- [R是对所有所使用的生物活性较低。