1.Researches On The Synthesis Of α-Acetyl α, β-Unsaturated Esters And Its Diels-Alder Reaction 2.Researches On The Synthesis Of Diphenyl Sulfide

Diels-Alder reaction,one of the most powerful synthetic tools for the construction of cyclohexene derivative,has been used widely in synthesis of medicines and natural compounds.α-acetyl-α,β-unsaturated esters are the important intermediate for preparing medicines,perfumes and other compounds.The synthesis ofα-acetyl-α,β-unsaturated esters catalyzed by amino acid with ionic liquids as solvent and its Diels-Alder reaction with cyclopentadiene have important academic significance.Diphenyl suffide is also an important organic synthesis intermediate. The Friedel-Crafts reaction of benzene and sulfur is a potential application of the method for the synthesis of diphenyl sulfide.In the researches on the synthesis ofα-acetyl-α,β-unsaturated esters and its Diels-Alder reaction.We have synthesizedα-acetyl-α,β-unsaturated esters catalyzed by amino acid with[BMim]BF₄ ionic liquids as solvent,The result shows that amino acid is a good catalyst. The best yield is up to 82%catalyzed by Lys.Then we have carried out its Diels-Alder reaction with cyclopentadiene by BMICl/ZnCl₂ ionic liquid as catalyst,discussed the influence of differentα-acetyl-α,β-unsaturated esters and synthesized five new compounds.The result shows that BMICl/ZnCl₂ ionic liquid has a good effection and stereoselective to the reaction.The yield of product is up to 89%and endo:exo is up to 96:4.In the researches on the synthesis of diphenyl sulfide.We have synthesized diphenyl sulfide by the Friedel-Crafts reaction of benzene and sulfur in the present of aluminum chloride,We used 1,3, 5-trimethylbenzene insteaded of benzene,carried out its Friedel-Crafts reaction with sulfur.Because of steric hindrance of 1,3, 5-trimethylbenzene,there were not thianthrene derivatives in products, but appeared three products,there were 2,4,6,2’,4’,6’- hexamethyl-diphenyl sulfide,2,4,6-trimethylbenzene thiophenol,2,4,6,2’,4’, 6’-hexamethyldiphenyl disulfide.The study showed that the ratio of three products was adjusted by amount of catalyst and reaction time.We have studied the ratio of three compounds with different amount of catalyst and reaction time and discussed the mechanism of this reaction.It is a new route for synthesis of 2,4,6,2’,4’,6’-hexamethyldiphenyl sulfide.