Síntese de pirazóis e desenvolvimento de novos líquidos iônicos derivados de componentes farmacologicamente ativos

Abstract

The synthesis of two series of N-substituted pyrazoles from the cyclocondensation reaction of β-enaminones ([R1C(O)C(R2)=CHN(Me2)], where R1 = Me, C6H5, 3-MeOC6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, thien-2-il; R2 = H, 2-MeO-C6H4) and 2-hydroxyethylhydrazine or 1-pentafluorophenylhydrazine was demonstrated. The reactions were performed in five ionic liquids ([BMIM][BF4], [BMIM][Br], [BMIM][OH], [HMIM][HSO4] e [BPy][BF4]) with different physical and chemical properties to establish the best reaction conditions. In addition, a Brönsted (HCl) and a Lewis catalyst (BF3●OEt2) and two molecular solvents (ethanol and water) were evaluated. The best ionic liquid found for all reactions was [BMIM][BF4]; molecular solvent ethanol for reaction with 2- hydroxyethylhydrazine; and water for reaction with 1-pentafluorophenylhydrazine. On the other hand, in the case of the reaction with 2-hydroxyethylhydrazine, BF3●OEt2 was found to be the best catalyst, while with 1- pentafluorophenylhydrazine, HCl, was found to be the best one, when comparing both reactions in [BMIM][BF4]. In general, the results showed it is advantage in yields and reaction time the use of ionic liquids in relation to molecular solvents. This work also shows the synthesis and characterization of a series of ionic liquids containing a pharmacological cation and/or anion. The new ionic liquids were synthesized from the metathesis reaction between the lidochaine, benzalkonium or didecyldimethylamonium salts, to furnish the cation part; and sodium diclofenac, sodium flurbiprofenate, sodium flufenamicate, sodium salicylate, sodium saccharinate and potassium acesulfamate, to furnish the anion part. The new ionic liquids were obtained in moderate to good yields (56-89%) and were identified and characterized through the NMR, DSC and TGA data.