Banca de QUALIFICAÇÃO: ROOSENILSON DIAS MUNIZ

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ROOSENILSON DIAS MUNIZ
DATE: 06/12/2024
TIME: 09:00
LOCAL: Qualificação por acesso remoto
TITLE:

“GREEN” SYNTHESIS OF FUNCTIONALIZED TETRAKETONES, CATALYZED BY Al(OH)3, WITH BACTERICIDAL EFFECT

KEY WORDS:

Tetracetone, ecological synthesis, aluminum hydroxide, bactericidal effect, tetraketones, aprotic solvents.

PAGES: 73
BIG AREA: Ciências Biológicas
AREA: Farmacologia
SUMMARY:

Introduction: Xanthene and its derivatives are an important class of organic compounds due to their pharmaceutical, biological and medical activities as anti-inflammatory, antibacterial, antiviral, antidepressant and antimalarial agents. They are antagonists of the paralytic action of Zoxazolamine and are used in photodynamic therapy. Thus, several synthetic methods have been reported for the preparation of xanthene derivatives. Objective: Therefore, the objective of this study was to perform the synthesis of tetraketones (xanthenedione) catalyzed by Al(OH)3 and evaluate their bacteriological effects against strains of Staphylococcus aureus (ATCC-6538P) and Pseudomonas aeruginosa (ATCC-9027). Methodology: A mixture of aldehyde (1 mmol), dimedone (2.5 mmol), Al(OH)3 (0.1 mmol) was heated at 80oC for 60 min. After completion of the reaction, the mixture was washed with water (15 mL). The crude product was purified by recrystallization from EtOH resulting in white crystals of pure 3a-k. 1H NMR and 13C NMR spectra were recorded on an Agilent Technologies 500/54 spectrometer, with CDCl3 as solvent. The reuse of Al(OH)3 as a catalyst for tetraketone synthesis was investigated. Results and Discussion: The novelty of this methodology lies in the application of the Al(OH)3 catalyst for the Knoevenagel-Michael cascade reaction of aromatic aldehydes and 1,3-cyclic diketones in water. The process was chemoselective and provided high yields of tetraketones under benign conditions. The catalyst maintained 80% of the initial activity in four cycles. Conclusion: The proposed method can be considered an alternative to existing syntheses of biologically active tetraketones that use expensive homogeneous heterogeneous catalysts.

COMMITTEE MEMBERS:
Externo ao Programa - 2222301 - ALEX DE NAZARE DE OLIVEIRA - nullExterno ao Programa - 3067465 - DAVID ESTEBAN QUINTERO JIMENEZ - nullPresidente - 1867989 - IRLON MACIEL FERREIRA