3 - Carboxyl And 3 - Cyano -7 - Substituted In The Synthesis Of Coumarin

Coumarins are a kind of very important chemical and pharmaceutical intermediates.They usually have good fluorescence performance,and are widely applied in fluorescent whitening agents,fluorescent dyes,as well as fluorescence probes.In order to be suitable with the development of fluorescence detection technology,diverse coumarins are being designed,synthesized and chosen.This thesis discusses the synthesis of 3-carboxy and 3-cyano coumarins and includes the following three aspects:In part one,three 3-carboxy coumarins were synthesized,and the optimum reaction conditions were studied.Furthermore,their fluorescence spectrum were determined.Taking 4-halo resorcinol as primary material,three substituted benzaldehyde,as follows 2,4-dihydroxy-5-fluobenzaldenyde(Ⅰa),5-chloro-2,4-dihydroxy benzaldehyde(Ⅰb) and 5-bromo-2,4-dihydroxy benzaldehyde(Ⅰc),were synthesized.Moreover,three 3-carboxy-7-hydroxy coumarins,as follows 3-carboxy-6-fluoro-7-hydroxy coumarin(Ⅱa),3-carboxy-6-chloro-7-hydroxy coumarin(Ⅱb) and 6-bromo-3-carboxy-7-hydroxy coumarin(Ⅱc),were synthesized via Knoevenagal reaction.WhereinⅠa andⅡa have not been reported in literature.Their structures were characterized by IR,~1H NMR,MS and elemental analysis.Also the optimum reaction conditions including formylation,method and reaction time of cyclization were studied to enhance the yield.In the end,their fluorescence spectrum are analyzed.In part two,a series of 3-cyano-7-substituted coumarins were synthesized, and also the optimum reaction conditions were studied.Taking 4-halo-resorcinol as primary material,two 3-cyano-7-hydroxy coumarins,as follows 3-cyano-6-fluoro-7-hydroxy coumarin,6-chloro-3-cyano-7-hydroxy coumarin,were synthesized by two steps.Both of them have not been reported in literature.On these bases,eight 3-cyano-7-substituted coumarins were synthesized according to the modification of 7-hydroxy by methyl iodide,ethyl iodide,2-bromo ethanol,1-bromo-2-chloroethane, benzyl chloride and methyl bromoacetate and characterized by IR,~1H NMR and elemental analysis.All of these compounds have not been reported in literature yet.At the same time,the optimum reaction conditions were studied.In part three,The crystal structure of 3-carboxy-6-fluoro-7-hydroxy coumarin is determined by X-ray diffraction and analyzed.The crystal structure belongs to triclinic system,space group P-1 with a=6.869(3)(?),b=6.996(3)(?), c=1.4315(6)(?),Z=2,F(000)=310.The final R=0.1114,wR=0.3090.It shows that the crystal structure is connected byπ-πstacking interactions.