Convenient synthesis, antimicrobial evaluation and molecular modeling of some novel quinoline derivatives

<i>α, β</i>-Unsaturated carbonyl compounds <b>2a, 2b, 3,</b> and <b>4</b> were synthesized by the Knoevenagel condensation between 2-substituted quionoline-3-carboxaldehyde <b>1a</b> and/or <b>1b</b> with active methylene compounds. In addition, the synthesis of azlactone is achieved starting from <b>1a</b> and <i>N</i>-acetylglycine. Synthesis of pyridine, pyrene, and pyrimidine derivatives <b>6</b>–<b>8</b> were accomplished via one-pot multicomponent reaction of <b>1b</b> with acetyl acetone, malononitrile, and ammonium acetate; acetophenone, malononitrile, and NaOH; or acetyl acetone and urea in acidic medium. The new synthesized compounds showed good antimicrobial activities. The DFT calculations have been used to predict the electronic properties of the studied compounds.

α,β-不饱和羰基化合物（α,β-Unsaturated carbonyl compounds）2a、2b、3和4，可通过2-取代喹啉-3-甲醛（2-substituted quionoline-3-carboxaldehyde）1a和/或1b与活性亚甲基化合物（active methylene compounds）之间的克诺文格尔缩合反应（Knoevenagel condensation）合成。此外，以1a与N-乙酰甘氨酸（N-acetylglycine）为起始原料，可实现吖内酯（azlactone）的合成。吡啶、芘及嘧啶衍生物6~8的合成，则通过1b分别与乙酰丙酮、丙二腈和乙酸铵；苯乙酮、丙二腈及氢氧化钠；或乙酰丙酮与尿素在酸性介质中进行一锅多组分反应（one-pot multicomponent reaction）完成。所合成的新化合物展现出良好的抗菌活性。本研究采用密度泛函理论（DFT, Density Functional Theory）计算，对所考察化合物的电子性质进行了预测。