含1，8-萘啶环和噻吩环的1，3，4-噁二唑的合成及抗菌活性研究

Synthesis and antibacterial activity of 1,3,4-oxadiazole derivatives containing 1,8-naphthyridine along with thiophene moiety

以2-氨基吡啶-3-甲醛和取代乙酰乙酸乙酯Friedlander缩合反应生成1,8-萘啶-3-基甲酸乙酯,经肼解反应得到1,8-萘啶-3-基甲酰肼为原料,对甲苯磺酸催化芳酰肼与噻吩-2-基甲醛缩合反应形成N-酰基腙中间体;该中间体不需要分离,二氯二氰基苯醌氧化条件下环合反应制备得到新型1,3,4-噁二唑衍生物,合成收率为83~91%,化合物结构经IR、~1HNMR、MS和元素分析等测试技术加以确证;初步的活性测试结果表明,目标产物对大肠杆菌、金黄色葡萄球菌和枯草杆菌等有一定的抗菌活性。

The starting material 1,8-naphthyridine-3-carbohydrazides,afforded from the Friedlander condensation of 2-aminonicoti- naldehyde and substituted ethyl aeetoaeetates and followed by treatment with hydrazine hydrate,was condensed with the thiophene- 2-carbaldehydes catalyzed by 4-methylbenzenesulfonic acid, in presence of 2,3-dichloro-5,6-dicyanobenzoquinone （DDQ） in order to synthesis of 1,3,4-oxadiazoles in one-pot protocol. The results indicated that intramoleeular eyelization was performed well via DDQ oxidative directly without further treatment and with good yields of 83 -91% respectively. The chemical structures of target compounds were confirmed by IR,1HNMR, MS spectra and elemental analysis. The investigation on preliminary bioassay showed that some of the target compounds had significant antibacterial activity- against Escherichia Coli, Staphylococcus Aureus and Bacillus Subtilis.