Study On The Synthesis Of Propargyl And Chalcone By Silver Carbonate Under Solvent Free Conditions

Propargylamines derivatives is an important intermediate in organic synthesis,but also an important intermediate in synthesis of natural products and biologically active compounds.Therefore,efficient and convenient synthesis of propargyl derivatives has attracted more and more attention.At present,there are many methods to synthesize propargyl derivatives,but there are some shortcomings,such as complex experimental operation,long reaction time,etc..The chemical structure of chalcone is 1,3-two phenyl ketone propylene,its natural compounds exist widely in maternal licorice,safflower and other plants.Not only it is an important intermediate for the synthesis of flavonoids,but also can be used for the synthesis of perfume and medicine.Chalcone has a wide range of biological activity because of the molecular structure is flexible and can bind with different receptors.The classical method of synthesizing chalcone is the use of strong base to catalyze the aldol condensation of acetophenone and its derivatives with benzaldehyde and its derivatives,but the yield is not high.The reaction without solvent has the advantage of being environment-friendly,fast in reaction rate and simple in post-treatment.In this study,silver carbonate was used to catalyze the reaction of benzaldehyde,phenyl acetylene and amines to produce Propargylamines derivatives and chalcone derivatives under solvent-free conditions.The main results is as follows:(1)The reaction of benzaldehyde,piperidine and acetylene was used as model reactants to explore the influence of amount of catalyst,reaction time and temperature under the solvent-free conditions.Optimal conditions are obtained as follows:Ag2CO3(3mmol%),110℃,10min.And we applied the method to various benzaldehyde、acetylene and different secondary amines.We also investigated the mechanistic pathway of this reation.We founded that all the reations afford the corresponding products in the yield of 45%-99%under the optimum conditions.A total of 29 products were synthesized and the structures of all known products were characterized and verified by 1H NMR,13C NMR and MS.(2)The reaction of benzaldehyde,piperidine and acetylene was used as model reactants to explore the influence of amount of catalyst,reaction time and temperature under the solvent-free conditions.Optimal conditions are obtained as follows:Ag2CO3(3mmol%),110℃,5 h.And we applied the method to various benzaldehyde、acetylene and different secondary amines.We also investigated the mechanistic pathway of this reation.We founded that all the reations afford the corresponding products in the yield of 30%-85%under the optimum conditions.A total of 15 products were synthesized and the structures of all known products were characterized and verified by 1H NMR,13C NMR and MS.In this paper,we investigated the reaction of benzaldehyde,amines and phenyl acetylene catalyzed by silver carbonate to produce Propargylamines and chalcone compounds under the solvent-free conditions.The advantages of the reation include:simple operation,mild conditions,solvent-free,easily obtained materials,good reaction compatibility and consistent with the concept of green chemistry.