Les liquides ioniques dans la réaction d’hétéro-cyclisation intramoléculaire de 2-aminochalcones et 2-époxychalcones.

Abstract

Two distinct themes were discussed during this thesis. The first concerns the synthesis and the use of ionic liquids in the intramolecular hetero-cyclization reaction of 2-aminochalcones and 1,2-epoxy-2-aminochalcones, while the second relates to the preparation and evaluation of antibacterial activity of quaternized poly-functionalized imidazolium salts. In the first part dedicated (reserved) to the isomerization reaction of 2-aminochalcones and 2- aminochalcones epoxides in ionic liquid environment, we have shown that the reaction proceeds correctly, and it is applicable to a wide range of substrates, without the use of an additional catalyst. the cyclization of The derivatives of (E) -1- (2-aminophenyl) -3-phenylpropen-2- en-1-one were tested in Three ionic liquids [bPy] [BF4], [bmim] [BF4] and [bmim] [PF6], among these [bmim] [BF4] is the most efficient (ratio LI / substrate: 10/1, temperature: 150 ° C, reaction time: 2.5 h). The 2-aryl-2,3-dihydroquinolin-4 (1H) -ones have been obtained with satisfactory yields (70-92%) in ionic liquid [bmim] [BF4], the (this) latter is recyclable three times with a slight decrease in its catalytic activity (83 → 64%). We also reported a practical and effective protocol for the synthesis of 2-aryl-3-hydroxy-1,2,3,4- tetrahydroquinolin-4 (1H) -ones by an intramolecular cyclization reaction of epoxyde 2- aminochalcone in ionic liquid at 120 ° C (LI ratio / substrate: 5/1, temperature: 120 ° C, reaction time: 6 h) of the four ionic liquids investigated, [bmim] [OTf] gave the best results in terms of cyclized product yield (35-93%). The structures of the compounds prepared were elucidated by the usual spectroscopic methods (IR, 1H NMR and C-13), and other elemental analysis and Xray diffraction for some of them. In the second part, a whole series of highly functionalized imidazolium salt derivatives were prepared (12 compounds) and their structures elucidated by the usual spectroscopic methods (IR, 1H NMR and C-13) and by X-ray diffraction for some of them. Most of these compounds were evaluated for their inhibitory capacity against four pathogenic strains: three Gramnegative (Escherichia coli, Salmonella thipymurium and Pseudomonas aeruginosa) and one Gram-positive (Staphylococcus aureus) using two methods: the inhibition zone and the determination of the minimum inhibitory concentration (MIC). The MIC results shows that iodine derivatives have inhibitory activity against Gram-negative strains, superior to brominated derivatives and compounds bearing a nitro group. Staphylococcus aureus (Grampositive bacteria) are significantly less sensitive to the action of the substrates used.