Banca de DEFESA: PRISCILA DE ALMEIDA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PRISCILA DE ALMEIDA SILVA
DATE: 14/07/2022
TIME: 14:00
LOCAL: Campus 6
TITLE:

KETALIZATION OF ETHYL LEVULINATE FOR THE PRODUCTION OF POTENTIAL BUILDING BLOCKS IN ORGANIC SYNTHESIS

KEY WORDS:

Ethyl levulinate. Pentaerythritol. Mesoporous Material. Ketalization.

PAGES: 100
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Campos de Coordenação
SUMMARY:

The intensification of environmental pollution caused by the constant consumption of products of fossil origin has been driving the development of substitutes from sustainable sources, such as those derived from lignocellulosic biomass. The objective of the present work was to synthesize an organic compound with the potential to be used as a building block in organic syntheses from the biomass derivative of ethyl levulinate through the ketalization reaction using the polyalcohol pentaerythritol in the presence of two types of catalysts, carboxylate of mesoporous niobium (CNbM), developed by our research group and the commercial cationic resin Amberlyst®15.

The development and characterization of CNbM was the object of study of our research group. Since this material proved to be very promising as a catalyst, it was chosen for testing in ketalization reactions within the scope of this dissertation. The cationic resin (Amberlyst®15) was used as a model catalyst since the literature correlates its use with high conversion rates and selectivity for the formation of the ketal group; with this, the results obtained between the two catalysts already described will be compared.
The present work developed a methodology for the synthesis of the CNbM catalyst. Through the characterization techniques by absorption spectroscopy in the infrared region, thermogravimetry, and X-ray diffraction, it was possible to observe evidence of the occurrence of coordination of the ligand to the metal and consequent obtaining material, based on literature data. The acidity measurement of the niobium-based material was equal to 0.94 mmolH+ gsol-1 which, compared to Amberlyst®15 (4.42 mmolH+ g-solid-1) appears to be of a more moderate nature.
The ketalization reaction between ethyl levulinate ester and pentaerythritol alcohol took place in a Dean Stark system and according to the characterization analysis by infrared absorption spectroscopy and mass spectrometry with electrospray ionization, the ketal of interest was formed.

BANKING MEMBERS:
Interno - EUDES LORENCON
Interna - ADRIANA AKEMI OKUMA
Externo ao Programa - CLEVERSON FERNANDO GARCIA