Study On Green Synthesis And Fluorescence Properties Of 3,4-dihydropyrimidin-2(1H)-one Derivatives

Dihydropyrimidinones(DHPMs)show significant biological and pharmacological activities.They can be used to treat high blood pressure,coronary heart disease,cardiovascular and other diseases.In addition,they exhibit a wide range of medicinal applications in the anti-microbial,anti-virus,sterilization,anti-inflammatory and other fields.The classical method for the synthesis of DHPMs was the Biginelli condensation reaction,involves the one-pot condensation of an aldehyde,a 3,4-dicarbonyl compound and urea in the presence of HCl.Thus,the Biginelli reaction attracted considerable attention.More extensive and deep research about the reaction conditions and synthesis methods have been carried.The scope of substrates were expanded too.Thus,some Biginelli-like reactions have also been reported and many new 3,4-dihydropyrimidinone derivatives have been synthesized.In this paper,the synthesis and research progress of 3,4-dihydropyrimidin-2(1H)-one derivatives were reviewed.It improved the synthetic methods of N1-unsubstituted 3,4-dihydropyrimidin-2(1H)-one derivatives,N1-substituted 3,4-dihydropyrimidin-2(1H)-one derivatives and 4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ones derivatives.The research results are presented as follows:1.Nineteen N1-unsubstituted 3,4-dihydropyrimidin-2(1H)-one derivatives were synthesized through a three-component one-pot synthesis of aromatic aldehydes(10 mmol),ethyl acetoacetate(methyl ester)(10 mmol)and urea(10 mmol)catalyzed by copper benzenesulfonate(2 mol%)at 80 ? under solvent-free conditions.The method has the advantages of simple operation,high yield,high catalyst activity and green environmental protection.The target compounds were characterized by 1H NMR,13C NMR,IR and elemental analysis.Some compounds were analyzed by scanning electron microscopy and fluorescence.Its structural morphology and fluorescent properties were demonstrated.2.Twenty-seven N1-substituted 3,4-dihydropyrimidin-2(1H)-one derivatives were synthesized through a three-component one-pot reaction of an aromatic aldehyde(10 mmol),an ethyl acetoacetate(methyl ester)(10 mmol)and a monosubstituted urea(10 mmol)catalyzed by copper benzenesulfonate(2 mol%))at 80 ? under solvent-free conditions.The experimental results indicate the advantages of simple operation,high yield,high catalyst activity and green environmental protection.The target compound were identified by 1H NMR,13C NMR,IR and elemental analysis.Some compounds were analyzed by scanning electron microscopy and fluorescence to demonstrated its structural morphology and fluorescent properties,which indicates that it is a potential fluorescent material.The structure of the three compounds was analyzed by single crystal X-ray diffraction.3.Twenty 4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ones derivatives were synthesized through a three-component one-pot reaction of an aromatic aldehyde(10 mmol),an acetophenone(10 mmol)and a urea(15 mmol)catalyzed by copper benzenesulfonate(5 mol%)at 90 ? under solvent-free condition.Compared with the reported methods,the reaction system has the advantages of short reaction time,high catalytic activity of the catalyst,solvent-free and green environmental protection.The target compound were identified by 1H NMR,13C NMR,IR and elemental analysis.