Abstract

Synthesis of new derivatives of 2-amino-4H-pyrans is reported via three-component reaction of α-ketoesters, active methylenes, and OH-acids in the presence of catalytic amount of piperidine at room temperature with high to excellent yields. The structure of synthesized compounds was characterized by FTIR, ¹H, ¹³C NMR spectroscopy, and mass spectrometry. Simplicity of procedure, mild reaction conditions, short reaction time, and easy separation of the products make this an interesting alternative to other reported approaches. Also, their antibacterial and antioxidant activities were evaluated against Staphylococcus aureus and Bacillus subtilis as Gram-positive bacteria and Escherichia coli and Pseudomonas aeruginosa as Gram-negative bacteria, as well as the radical scavenger DPPH. Among these compounds, 4l including CO₂Et substituent and 6-methyl-2H-pyran-2-one moiety showed the highest antioxidant and antibacterial activities.

Graphic abstract

中文翻译：

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α-酮酸酯和活性亚甲基与OH-酸的三组分反应合成新的2-amino-4 H -pyran衍生物的研究及其抗菌和抗氧化活性的评估

摘要

据报道，在室温下，在催化量的哌啶存在下，通过α-酮酸酯，活性亚甲基和OH-酸的三组分反应，可以合成2-氨基-4 H-吡喃的新衍生物，产率高至优异。合成的化合物的结构通过FTIR，¹ H，¹³ C NMR光谱和质谱进行表征。操作简便，反应条件温和，反应时间短，产物易于分离，这使其成为其他已报道方法的有趣替代方法。此外，还评估了它们作为革兰氏阳性菌对金黄色葡萄球菌和枯草芽孢杆菌的抗菌和抗氧化活性。大肠杆菌和铜绿假单胞菌为革兰氏阴性细菌，以及自由基清除剂DPPH。在这些化合物中，包括CO ₂ Et取代基和6-甲基-2 H-吡喃-2-酮部分的4l具有最高的抗氧化和抗菌活性。

图形摘要