In this work the alkylation of 4,6-dimethylpyrimidin-2(1H)-thione with ethyl bromoalkanoates was described. It was found the reactions in the present of potassium carbonate in boiling acetonitrile gave rise to corresponding S-alkylated derivatives. Under treatment of ethyl 2-(4,6-dimethyl-2-pirimidinylthio)alkanoates with excess of hydrazine hydrate the corresponding hydrazides were prepared. Further refluxing with aromatic monocarbonylic compounds led to formation of corresponding hydrazones. By the spectral data hydrazones exist as mixtures of E/Z conformers. The purity of the synthesized compounds was controlled by thin layer chromatography. The structure was proved by 1H NMR, IR and UV spectra.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, we explored new methodologies to obtain β-enamino carbonylic compounds derived from 1,3-dicarbonyl and α-amino acids using microwave and solvent free conditions. The β-enamino carbonylic compounds were prepared by the reaction of 1,3- dicarbonyl compounds, acetilacetone, ethyl acetoacetate or ethyl 2-oxo-1- cyclopentanecarboxylate with α-amino esters hydrochlorides derived from glycine, Lalanine, L-serine and L-proline. The reactions were performed with or without solid support (K-10 or KSF) using microwave irradiation. An addition aim of this study is the investigation of the reactivity of the β-enamino carbonylic compounds, with the possibility of creating alternative synthetic routes for heterocyclic compounds. The reactivity of the acyclic β-enamino carbonylic (C,N-dinucleophiles) was evaluated by reactions with the 1,2-diketones. To evaluate the influence of the group -CHR1COOEt (N- substituted) on the reactivity of the β-enamino carbonyl compounds obtained by reduction reactions, we used NaBH4/EtOH, which is effective for the selective reduction of the derived compounds of the acetilacetone or ethyl 2-oxo-1-cyclopentanecarboxylate giving their respective β-hidroxyenamino products. The reactivity of diethyl-3-benzylamino-2-pentenedioate was also evaluated using NaBH4, where the methylene acetate fragment (-CHR1COOEt), instead of being bonded to the nitrogen atom, is bonded to the β-carbon atom. This model allows us to evaluate the complexation of the nitrogen atom and carbonyl carbon atom with the tetrahydroborate and subsequent hydride transfer allowing a comparison with the reductions mentioned previously. The antimicrobial activity of the cyclic β-enamino carbonylic coumpounds, β- hydroxyenamino and of the heterocyclic 2-pyrrolin-5-one obtained, was investigated by the Bioautography method against different indicative microorganisms. / Neste trabalho buscamos estabelecer metodologias para obtenção de compostos β-enamino carbonílicos, derivados de 1,3-dicarbonílicos e α-aminoácidos utilizando energia de microondas e ausência de solvente. Os compostos β-enamino carbonílicos foram obtidos empregando compostos dicarbonílicos como acetilacetona ou acetoacetato de etila ou 2-oxo-1-ciclopentanocarboxilato de etila com cloridratos de α-aminoésteres derivados da glicina, Lalanina, L-serina e L-prolina. Estes compostos foram obtidos empregando reações em forno de microondas doméstico associado ou não a suporte sólido (K-10 ou KSF). Nossos estudos também tem por objetivo uma aplicação imediata na investigação da reatividade dos sistemas β-enamino carbonílicos obtidos, visualizando a possibilidade de criarmos rotas alternativas para obtenção de compostos heterocíclicos. Portanto, neste trabalho, com o propósito de obter compostos N-heterociclos, avaliou-se a reatividade dos β-enamino carbonílicos acíclicos (C,N-dinucleófilos), através de reações com 1,2-dicetonas. Com o intuito de avaliarmos a influência do grupo -CHR1COOEt (N-funcionalizado) na reatividade dos β-enamino carbonílicos obtidos em reações de redução, empregamos NaBH4/EtOH, o qual foi efetivo na redução seletiva dos compostos derivados da acetilacetona e 2-oxo-1-ciclopentanocarboxilato de etila levando a obtenção dos respectivos β-hidroxienaminos. A reatividade do composto 3- benzilamino-2-pentenodioato de dietila também foi avaliada utilizando NaBH4, onde o fragmento metileno acetato (-CHR1COOEt), ao invés de estar ligado ao Nitrogênio está ligado ao carbono β. Este modelo nos permite avaliar a complexação do Nitrogênio e da carbonila com o tetrahidroborato e posterior transfência do hidreto possibilitando estabelecer uma comparação com as reduções efetuadas anteriormente. A investigação da atividade antimicrobiana dos compostos cíclicos como os β-enamino carbonílicos, β-hidroxienaminos e do heterociclo 2-pirrolin-5-ona obtidos neste trabalho, foi realizada através do método de Bioautografia, frente a diferentes microorganismos indicadores.