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.