Synthesis of exocyclic enaminone-based thiohydantoins as potent antifungal agents

A highly efficient and stereoselective synthesis of (E)-5-(dimethylamino)methylene thiohydantoins is herein reported. It was carried out through a one-pot, two-step reaction between methyl N-arylglycinates, isothiocyanates, and DMFDMA under microwave irradiation. The thermal and catalyst-free reaction of the (dimethylamino)methylene thiohydantoins with anilines led to the stereoselective formation of (E)-(anilinomethylene) thiohydantoins. The antifungal activity of the products was evaluated with a series of five Candida spp., finding a potent effect, even against a fluconazole-resistant C. glabrata strain. The docking studies suggest that this inhibitory effect is due to the binding of the compounds to the active site of fungal HMGR.