Banca de DEFESA: JAMILLE SILVEIRA MATOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JAMILLE SILVEIRA MATOS
DATA : 29/07/2019
HORA: 14:00
LOCAL: instituto de quimica
TÍTULO:

Synthesis and reactivity of 3-acetylthioenaminones

PALAVRAS-CHAVES:

Thioeneminones. Solvent-free. Alternative green route.

PÁGINAS: 111
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Síntese Orgânica
RESUMO:

The interest in the synthesis of new bioactive molecules and the research for new methodologies in line with the principles of Green Chemistry has been increasing in the last decades. Thioeneminones are densely functionalized intermediates with several reactive centers and are important building blocks for a variety of heterocyclic compounds, such as pyrazole, isothiazole and tetrazole. The objective of this work is to study green methodologies of synthesis of thioenaminones and to investigate their reactivity to different nucleophiles and oxidant agent to develop a series of new molecules with biological activity. Two methodologies were developed for the synthesis of these compounds under solvent-free condition, low temperatures and solid support-free. The first methodology involves the reactions of enaminones with phenyl isothiocyanate under solvent-free condition at room temperature. The second methodology involves the same reaction condition under ultrasound irradiation. From the first methodology it was possible to synthesize different thioenaminones in yields of 18% and 78%. In most reactions afforded a mixture isomeric thioenaminones Z/E in the ratio 3:1. To investigate the reactivity of these compounds the thioenaminones derivatives were synthesized from the mixture isomeric Z/E with hydrazine and iodine, with sodium azide only the isomer E was used. In the reaction with N₂H₄ 80% in ethanol it was possible to obtain in one step the corresponding pyrazolone and pyrazole in 15% and 34% yield, respectively. In the reaction with I₂ and K₂CO₃ in acetonitrile the isothiazole was obtained in 17% yield. In the reaction with NaN₃ and Bi(NO₃)₃.5H₂O in acetonitrile by microwave, 120°C, 150W and 5 min the tetrazole was obtained in 26% yield. The proposed methodology for the synthesis of thioenaminone is according with the principles of Green Chemistry and was developed with good yields. Of the 20 molecules synthesized in this work 9 are unpublished in the literature.

MEMBROS DA BANCA:
Interno - 1215450 - SILVIO DO DESTERRO CUNHA
Interno - 1276681 - RONAN BATISTA
Interno - 285863 - JUCENI PEREIRA DE LIMA DAVID
Interno - 1148522 - ELIANE DE OLIVEIRA SILVA
Externo à Instituição - FERNANDA ANDREIA ROSA - UEM
Externo à Instituição - DIMAS JOSÉ DA PAZ LIMA - UFAL