Síntese, caracterização e avaliação da toxicidade em Allium cepa da acetanilida e derivados

Abstract

Acetanilide is a compound from the amide class and was used as a drug due to its analgesic and antipyretic properties. However, even in the first years of its use, the associations were a toxic substance and their use was discontinued. Thus, a compound analogue of acetanilide, N-(4-hydroxyphenyl) ethanamide known commercially as Paracetamol, began to be used and has been widely used today. Paracetamol has biological activity similar to its predecessor, but is safe for moderate use. Furthermore, it is known that most of the substances present in current medicines have the amide group in their compositions, which act directly on the central nervous system and have several biological activities. In this sense, in the present work the synthesis of acetanilide (1), N-(4-methylphenyl)acetamide (6), N-(2-methylphenyl)acetamide (7) was carried out through the occurrence of nucleophilic acyl substitution and the N-(4-nitrophenyl)acetamide (8) through the occurrence of electrophilic aromatic substitution. The synthesized compounds were obtained in yields of 78%, 90%, 40% and 70% respectively. All compounds were characterized by measuring the melting point (PF) and Hydrogen and Carbon Nuclear Magnetic Resonance spectroscopy (1H and 13C NMR), and the analyzes carried out are consistent with literature data. Furthermore, studies were carried out to verify the toxicity of compounds (1), (6), (7) and (8) at concentrations of 100 and 250 mg/L using the Allium cepa bioassay. The roots were kept in contact with the solutions (100 mg/L concentration: 0.5mL of ethanol:100mL of water and 250 mg/L concentration: 1.25mL of ethanol:100mL of water). After a period of 10 days in contact with the solutions, an analysis of the results declared that at these concentrations all the compounds were toxic, inhibiting root growth.