Síntese e ensaios de estabilidade de derivados diidropiridínicos

Abstract

Dihydropyridines are heterocyclic organic compounds characterized by a six-membered ring containing a nitrogen atom in its structure and two insaturations, representing a reduced form of the pyridine ring. These molecules exhibit a wide range of potential pharmacological applications, including antimicrobial, antioxidant, antitumor, antitubercular activities, among others. However, for the safe use of this class of compounds as active pharmaceutical ingredients in the pharmaceutical industry, it is essential to understand their resistance to chemical degradation. Therefore, the aim of this work was to synthesize one dihydropyridine, one hexahydroquinoline, and six different decahydroacridines, and to characterize them by FTIR, DSC, and NMR, as well as to evaluate their resistance to degradation. The synthesized products were then subjected to forced degradation tests in order to determine their chemical stability and to verify whether the lateral rings present in the studied derivatives positively or negatively influence their degradation behavior. Ultraviolet spectra of two of the synthesized molecules were obtained and compared with the spectra of the products after thermolytic and photodegradation tests, by analyzing changes in absorption bands, which would indicate that the analyzed compounds underwent degradation processes. The thermolytic tests demonstrated that both molecules exhibit high resistance to temperature over short periods of time, whereas in the photodegradation tests it was determined that the hexahydroquinoline shows greater resistance than the decahydroacridine. This behavior is mainly attributed to the availability of carbonyl groups in the molecule to stabilize radical intermediates.