Síntese de tetraidro-beta-carbolina em micro-ondas: uma abordagem verde
Data
2024-06-07
Autores
Souza, Bruno Casagrande de 
Orientadores
Craveiro, Marcus Vinicius
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
As tetraidro-β-carbolinas são uma subclasse dos alcalóides indólicos, possuem uma estrutura tricíclica pirido[3,4-b]indólica. Esta estrutura pode ser encontrada em moléculas de fonte natural e em fármacos comerciais. Devida a sua importância, há diversas metodologias para a sua preparação, sendo a reação de Pictet-Spengler a mais utilizada. A química verde é uma área da química composta por diretrizes que buscam guiar o desenvolvimento de metodologias para que usem e gerem a menor quantidade de resíduo. Neste trabalho realizou-se um estudo metodológico visando à síntese de derivados de tetraidro-β-carbolinas a partir da triptamina e aldeídos com diferentes substituintes utilizando condições ambientalmente amigáveis: Solvente verde alternativo dimetilcarbonato (DMC) e aquecimento por micro-ondas. Três derivados foram sintetizados com tempos reacionais variando-se entre 4 – 15 min, com rendimentos entre 74 – 98 %. Adicionalmente, a diminuição do excesso dos aldeídos foi estudada (de 2 para 1,1 equiv.) para abordar a eficiência mássica reacional. Esses testes chegaram a: 74% de rendimento a 120 ºC, 8 min, 70% eficiência ótima para o primeiro derivado; 98% de rendimento, 120 ºC,15 mim, 70% de eficiência ótima para o segundo derivado; 71% de rendimento, 120 ºC, 4min, 70% de eficiência ótima para o terceiro derivado.
Tetrahydro-β-carbolines are a subclass of indol alkaloids, with a pyrido[3-4-b]indole tricyclic structure. This structure can be found in a plethora of naturally occurring molecules and in commercial drugs. Due to their importance, many methodologies have been developed with different approaches for its synthesis, the Pictet-Spengler reaction being the most widely used. Green chemistry can be defined as principles and guidelines that seek to guide the design of new methodologies so that they use and generate the least amount of waste. In this work, a methodological study was carried out to synthesize tetrahydro-β-carboline derivatives from tryptamine and aldehydes with different substituents using environmentally friendly conditions: dimethyl carbonate (DMC) as an alternative green solvent and microwave heating. Three derivatives were successfully synthesized with reaction times varying between 4 - 15 min, with yields between 74 - 98 %. In addition, decreasing the excess of aldehydes was studied (from 2 to 1.1 equiv.) to address the reaction mass efficiency. These tests reached: 74% yield at 120 ºC, 8 min, 70% optimum efficiency for the first derivative; 98% yield, 120 ºC, 15 min, 70% optimum efficiency for the second derivative; 71% yield, 120 ºC, 4 min, 70% optimum efficiency for the third derivative.
Tetrahydro-β-carbolines are a subclass of indol alkaloids, with a pyrido[3-4-b]indole tricyclic structure. This structure can be found in a plethora of naturally occurring molecules and in commercial drugs. Due to their importance, many methodologies have been developed with different approaches for its synthesis, the Pictet-Spengler reaction being the most widely used. Green chemistry can be defined as principles and guidelines that seek to guide the design of new methodologies so that they use and generate the least amount of waste. In this work, a methodological study was carried out to synthesize tetrahydro-β-carboline derivatives from tryptamine and aldehydes with different substituents using environmentally friendly conditions: dimethyl carbonate (DMC) as an alternative green solvent and microwave heating. Three derivatives were successfully synthesized with reaction times varying between 4 - 15 min, with yields between 74 - 98 %. In addition, decreasing the excess of aldehydes was studied (from 2 to 1.1 equiv.) to address the reaction mass efficiency. These tests reached: 74% yield at 120 ºC, 8 min, 70% optimum efficiency for the first derivative; 98% yield, 120 ºC, 15 min, 70% optimum efficiency for the second derivative; 71% yield, 120 ºC, 4 min, 70% optimum efficiency for the third derivative.