Divergent Synthesis of Novel 3(5)-Aminoazole–Benzopyrone Hybrids and their Evaluation as α-Glucosidase Inhibitors

An efficient approach has been developed for the trapping in situ generated benzopyrone-based ortho-quinone methide intermediates by 3- and 5-amino pyrazoles or isoxazoles. In cases of naturally occurring phenolic Mannich bases, hybrid compounds between the azole and flavonoid, namely, coumarin, chromone, isoflavone, and aurone were synthesized in moderate to good yields. It is remarkable that depending on 3- or 5-position of the amino group, the reaction led to the formation of C-4 or 3-NH substituted azole derivatives, respectively. In vitro studies showed that some of the obtained compounds bearing 5-aminoisoxazole part exhibit inhibitory activity towards α-glucosidase with IC₅₀ values in the micromolar range.