One-pot Multicomponent Synthesis Of Novel Coumarin Derivatives

Coumarins, whose structural core comprises a 2H-1- benzopyran-2-one scaffold, constitute a major class of widely distributed O-heterocyclic natural products isolated from many fruits, vegetables, spices and herbs. Natural and synthetic coumarins have been found to exhibit versatile pharmacological activities, acting as antineoplastics, anticoagulant, antidepressants, anti-inflammatories, antifungals, antihypertensives, antiasthmatics. In addition, the intrinsic photophysical characteristics of coumarins and derivatives enable their use as fluorescent brightening agents, organic light emitting diodes, optical sensors, light harvesting materials, non linear optical materials and fluorogenic probe in biological imaging.As a valuable intermediates in modern organic synthesis, pyran is one of the most remarkable and important heterocyclic scaffolds. It also possesses wide range of pharmacological activities and act as vasorelaxant, antitumor, antibacterial, antimicrobial and anti-inflammatory agents.The heterocyclic spirooxindole ring system is a kind of frequently encountered structural motif in many natural alkaloids. A number of spirooxindole scaffolds deliver important pharmacological activity such as vasodilatory, hypoglycaemic, analgesic and antipyretic activities.One of the desirable goals in organic chemistry is assembly of simple and readily available precursor molecules into complex products in facile execution. Multicomponent reactions(MCRs) have gained considerable attention not only due to MCRs enable expedient and efficient assembly of molecules of structural complexity and diversity in one-pot operations in facile execution, but also with high atom economy, and selectivity. Multicomponent reactions(MCRs) have facilitated many fascinating and challenging transformations in organic synthesis. These reactions cast off the process of isolation and purification of intermediates and decrease waste generation, therefore enhancing the greenness of transformations. MCRs have been emerging as powerful means in the synthesis of complex biologically and medicinally important compounds.In chapter one, we described detailed information about the synthesis and applicaton of coumarin derivatives.In chapter two, we described synthesis of β-keto ester coumarins and studies of UV absorption spectra and fluorescence spectra of it.In chapter three, we reported one-pot three component synthesis of coumarin-4H-pyran conjugates under CTAC catalysis.In chapter four, we reported efficient one-pot catalyst-free synthesis of novel fluorescent coumarin- spiro[indoline-3,4’-pyran] conjugates via three-component domino reaction in aqueous medium.