A short review on the synthesis of oxazolo/thiazolo/imidazolocoumarins and their biological activities

The coumarins are found in both natural and synthetic compounds that display a broad spectrum of biological properties including anticoagulant, antibacterial, antioxidant, and antiviral as well as anticancer properties. On the other hand, oxazole, thiazole, and imidazole are also important for their antimicrobial, anticancer, antitubercular, anti-inflammatory, antidiabetic, antiobesity properties and act as topoisomerase inhibitors, microtubule polymerization inhibitors and cytochrome P450 enzymes inhibitors. It has been reported that the coumarin fused oxazole, thiazole, and imidazole derivatives were found to exhibit antibacterial, antioxidant, antitumor, anticonvulsant, anti-inflammatory, anticancer as well as antimetastatic activity. The main purpose of this review is to highlight different synthetic methodologies for the synthesis of oxazolo/thiazolo/imidazolocoumarins (either angular or linear) and their biological importances reported in the literature. Several methods for the synthesis of such fused compounds in which 3-nitro/aminocoumarin derivatives are mostly used as the starting material, have been described in the literature.