Efficient pyran derivatives synthesis in DES medium and their antimicrobial evaluation as inhibitors of mycobacterium bovis (BCG)

An ecofriendly one-pot three-component reaction of 1,3-dicarbonyl compounds, aromatic aldehydes and malononitrile was carried out in deep eutectic solvent (DES) based on choline chloride, to synthesize highly functionalized pyran derivatives under moderate conditions. The main advantages of this approach are mild reaction conditions, high yields, relaxed workup without chromatographic purification steps or extraction and easily reusable of DES’s. Then, these compounds were evaluated for anti-mycobacterium activity against Mycobacterium bovis (Bacillus Calmette–Guerin). The preliminary results indicated that most of the tested compounds showed relatively good activity against the test organism. The compounds 4a, 4c, 4e, 4n demonstrated the high activities against Mycobacterium (0.044–0.084 μM/mL) and 4k showed highest activity (0.033 μM/mL). The commonalities of these compounds are having a chlorine atom on the ring which is located on position 4 of the 4H-pyran structures.