Synthesis and Antifungal Activity of 4‐ and 6‐(1 H ‐Pyrrol‐1‐yl) Coumarins, and their Thiocyanato Derivatives

Abstract

Facile and efficient syntheses of 4‐(1H ‐pyrrol‐1‐yl)‐coumarins and 6‐(1H ‐pyrrol‐1‐yl)‐coumarins from the corresponding aminocoumarins are reported. The transformations were optimized and their corresponding scope and limitations were assessed. Selected (1H ‐pyrrol‐1‐yl)‐coumarins were further subjected to a mild thiocyanation, undergoing selective functionalization on the pyrrole nucleus. A set of 10 differently substituted compounds was submitted to activity testing against various fungal strains. It was found that the introduction of a SCN moiety increased the antifungal activity, turning some compounds into fungicidal agents, to the point that one of the thiocyanato derivatives displayed an antifungal profile comparable to those of fluconazole and nystatin.