Study of Preparation and Properties of Imidazolium Betaines

To investigate the posibility for the preparation of 1,3-dicarboxyalkyl( benz)imidazolium betaines a number of monosubstituted 1-carboxyalkyl(benz)imidazoles has been prepared (I-X) and their basic pKa value determined. The betaines (XI~XIV) can be prepared only from the imidazole derivatives which had basic (N3) pKa values above 3--4 pKa units. !-Substituted benzimidazoles decomposed under reaction conditions employed ·for quaternization, yielding N,N\u27-dicarboxyalkyl o-phenylenediamines. Dimethylformamide when used as the solvent under highly basic reaction conditions reacted with halogen carboxylic acid.s giving · rise to the formation · of betaines of dimethyl-dicarboxyalkyl amines (XV, XVI) and hydrochlorides of dimethyl-carboxyalkyl amines (XVII, XVIII), respectively. The reaction course of 1,3-disubstitution is briefly discussed, as well as some chemical and physical properties of the betaines are described

Study of Preparation and Properties of Imidazolium Betaines

To investigate the posibility for the preparation of 1,3-dicarboxyalkyl( benz)imidazolium betaines a number of monosubstituted 1-carboxyalkyl(benz)imidazoles has been prepared (I-X) and their basic pKa value determined. The betaines (XI~XIV) can be prepared only from the imidazole derivatives which had basic (N3) pKa values above 3--4 pKa units. !-Substituted benzimidazoles decomposed under reaction conditions employed ·for quaternization, yielding N,N\u27-dicarboxyalkyl o-phenylenediamines. Dimethylformamide when used as the solvent under highly basic reaction conditions reacted with halogen carboxylic acid.s giving · rise to the formation · of betaines of dimethyl-dicarboxyalkyl amines (XV, XVI) and hydrochlorides of dimethyl-carboxyalkyl amines (XVII, XVIII), respectively. The reaction course of 1,3-disubstitution is briefly discussed, as well as some chemical and physical properties of the betaines are described

N 1-Substitution in 2-Methyl-4(5)-Nitroimidazole. II.

During the syntheses of some new derivatives of 2-methyl-4(5)nitroimidazole with potential antitrichomonal activity, we have noticed that the substitution on N 1 did not always depend on the pH of the medium, as it has been stated by Pyman1- 4 and Grimison et al.5- 8 • Therefore, we have approached the syste matic investigations of the influence of pH on the formation of t h e 4-nitro and 5-nitroisomers of N1- s ubstituted 2-methyl-4(5)-nitroimidazole. The results obtained indicate that the conclusion of Pyman1- 4 is valid only when strongly alkylated agents are applied, e. g. dialkylsulphates and alkyl tosylates9, since, with other alkylated agents this conclusion could be applied only with restrictions· In addition, we have measured pK:i constants for some isomer pairs prepared, in order to apply the statem ent of Grimison et al.6 that the tautomer ratio, calculated from pKa values, determines the ratio of the isomers in the product mixture . In spite of the fact that the pKa measurements were in goo d accordance with some earlier perform e d6 ,10,15, N 1-substitution with a number of alkylating agents indicate that the statement of Grimison et al.5- 8 is of importance only for alkylation with dimethylsulphate under strictly d e termined conditions

Utilizando o testbed Smart City para treinar alunos de engenharia em tópicos de gerenciamento de rede durante a pandemia de COVID-19

Com as imensas oportunidades para tornar uma rede de comunicação programável, a virtualização de funções de rede e redes definidas por software estão ganhando força tanto na indústria quanto nos círculos de pesquisa, sendo um conjunto de habilidades fundamentais para engenheiros elétricos e cientistas da computação. Portanto, neste artigo, apresentamos e avaliamos a estrutura educacional para o ensino prático de Service Function Chaining (SFC) para alunos de graduação com o objetivo de prepará-los para o futuro mercado de Tecnologias de Informação e Comunicação (TIC) e redes de comunicação que demandará profissionais habilidosos na área. A estrutura educacional foi projetada para o curso de Gerenciamento de Rede da Universidade de Antuérpia, com o objetivo de preencher a lacuna entre os conceitos de programabilidade de rede aplicados na indústria e os ensinados na Universidade. Avaliamos a estrutura educacional com duas extensas pesquisas como feedback dos alunos que nos deram a oportunidade de medir e quantificar a experiência e satisfação dos alunos com a estrutura. Em particular, com base no ambiente desafiador imposto pelo COVID-19, identificamos as lacunas neste quadro educativo e abordar melhorias nas componentes teórica e prática de acordo com as necessidades dos alunos. Nossa estrutura educacional e a avaliação minuciosa servem como uma orientação útil sobre como modernizar os cursos de engenharia e acompanhar o ritmo da tecnologia