Study On The Synthesis And Antifungal Activities Of 4,7-dihydroxycoumarin Heterocyclic Derivatives

Coumarin and its derivatives are considered nowadays an important class of organic compounds due to their wide spectrum of biological activities such as antibacterial,antifungal,anti-inflammatory,anticoagulant,anti-HIV and antitumor agents.Thus,coumarins in medicine,agriculture fields have been widely used.In this thesis,4-hydroxycoumarin and 4,7-dihydroxy coumarin as raw material,through Pechmann condensation reaction,nine of pyrano[3,2-c]benzopyran-2,5-ones were synthesized,and then 23 of 8-alkoxypyrano[3,2-c]chromen-2,5-diones were synthesized by Williamson reaction.furo[3,2-c]benzopyran-4-one derivatives were obtained via a tandem alkylation/intramolecular aldol reaction with 4-hydroxycoumarin or 4-hydroxy-7-alkoxycoumarin and a-chloroketones.Target product structures were confirmed by IR,NMR(1H and 13C),mass spectrometry and elemental analysis.Antifungal activity assay.The preliminary antifungal activities of synthetic coumarin fused furan heterocyclic compounds against Botrytis cinerea,Collecterichum capsica,Alternaria solani,Gibberella zeae and Rhizoctonia solani were analysed.The results indicate that,coumarins fused furan were active in against all five tested fungi,what's more,the alkoxy at 7-position is critical for maintaining the antifungal activity.And the precision toxicity of these highly active compounds was further tested,and the compound 7-Allyloxy-3-methyl-4H-furo[3,2-c]chromen-4-one is the most excellent antifungal effect.