One-pot three-component synthesis of thioether linked 4-hydroxycoumarin-benzothiazole derivatives under ambient condition and evaluation of their biological activity

An efficient and convenient method has been outlined for the synthesis of 3-[(1,3-benzothiazol-2-ylsulfanyl)(phenyl)methyl]-2H-chromen-4-ol derivatives via a one-pot three-component Knoevenagel condensation reaction between 4-hydroxycoumarin, substituted aldehyde, and 2-mercapto benzothiazole in the presence of 10 mol% L-proline as an efficient catalyst in ethanol. The structure of all the newly synthesized chromone derivatives was confirmed by different spectroscopic techniques like IR, 1H NMR, 13C NMR, and LC-MS. Further, all the derivatives were screened for their biological activities such as anti-mycobacterial activity, in vitro antioxidant activity, anticancer activity, and molecular docking studies.