Síntese de amidas poliaromáticas conduzidas por processo verde e investigações farmacológicas

Abstract

Amides are a group of organic substances that have a nitrogen atom attached to a carbonyl group (C=O), which can be primary, secondary or tertiary. Aromatic amides find a wide spectrum of use, for example, in repellents, in the composition of drugs, in vitamins, among others. The objective of this work was to synthesize and characterize three aromatic tertiary amides derived from benzoic acid, namely N,N-diphenylbenzamide (P1), N-phenyl-N-1- naphthylbenzamide (P2) and N-phenyl-N-2-naphthylbenzamide (P3) and to evaluate the qualitative and toxic antioxidant potential of the products against Artemia salina Leach larvae. The three syntheses were carried out under the same conditions, using the classic SchottenBaumann method, through a simple methodology aligned with the so-called “Green Chemistry”. The characterization by melting point revealed concordant values for the products and different values for the starting materials. The three syntheses provided good reaction yields. Analysis by thin layer chromatography (TLC), using plates containing silica gel G 60 and eluting in chloroform, revealed that the samples found a good level of purity. The infrared spectra of the substances give the main expected stretches for the products (N-H, C=O amide, C-N and C=C aromatic). Analysis of qualitative antioxidant activity did not reveal antioxidant potential for the three products, compared to the rutin standard, which was expected by the reaction proposal. Finally, thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis showed similar behavior for P1 and P2, while for P3 there was a difference in behavior due to its molecular geometry.