Synthesis and Antimicrobial Evaluation Studies of Novel Coumarin Derivatives

Abstract

Coumarins (2H-1-benzopyran-2-one) are naturally occurring benzopyrano derivatives. newlineCoumarins comprise a very large class of compounds found throughout the plant newlinekingdom. They are found at high levels in some essential oils, particularly cinnamon, newlinebark oil (7,000 ppm), cassia leaf oil (up to 87,300 ppm) and lavender oil. Coumarins are newlinealso found in fruits (e.g. bilberry, cloudberry), green tea and other foods such as chicory. newlineIn addition, these compounds are involved in the actions of plant growth hormones and newlinegrowth regulators, the control of respiration, photosynthesis, as well as defense against newlineinfection. Coumarins have long been recognized to possess anti-inflammatory, newlineantioxidant, anti allergic, hepatoprotective, anti-thrombotic, anti-viral and anticarcinogenic newlineactivities. Therefore, the object of the present study is to synthesize new newlinecoumarins with a view to assess their anti-bacterial activities. newlineThe thesis is comprised into Three Sections. newlineSECTION - A newlineUnit 1: Introduction. newlineThis unit deals with the general introduction of Coumarin like naturally occurring newlinecoumarins moieties and its physiological importance. Along with this, many synthesized newlineCoumarin analogues found pharmacologically active chemical entities. It helps to newlineunderstand the kind of chemistry known in the literature regarding Coumarin newlineheterocyclic ring system. newlineUnit 2: Synthesis of Coumarins by Pechmann Condensation. newlineThis unit is further divided into two parts. newlinePart 1: Solvent free Synthesis of Coumarins Derivatives by Pechmann Condensation newlineusing PMA:SiO2 supported BF3:OEt2 catalyst and Perchloric acid modified cellulose newlinecatalyst at Room Temperature newlineThis part describes the synthesis of Coumarins (2H-1-benzopyran-2-one) by Von newlinePechmann reaction. Upon condensation of substituted phenols with ethylacetoacetate in newlinepresence of conc. sulfuric acid afford coumarins. This method was modified and newlinesimplified by using green pathway in solvent free condition in presence of catalyst like newlinePMA:SiO2 supported BF3:OEt2 and further by using Perchloric acid modifie