Reactions of salicylaldehydes with activated terminal alkynes in aqueous media: synthesis of 3-substituted 4-hydroxy chromenes as potential cytotoxic agents†
Abstract
Terminal alkynes containing ester, amide or ketone moieties have been reacted with salicylaldehydes in the presence of DABCO affording a direct and single-step method for the regioselective synthesis of 3-substituted 4-hydroxy-4H-chromenes in aqueous 1,4-dioxane. A number of novel chromene derivatives were prepared in good yields using this methodology some of which showed cytotoxic properties when tested against cancer cells.