IF 0.3 4区化学

Afinidad Pub Date : 2013-01-01 DOI: 10.13140/2.1.2364.2244

L. A. Trujillo, J. Santos, Nuria Calero, M. C. Alfaro, José Muñoz

{"title":"Caracterización reológica de una suspoemulsión comercial para uso agroquímico","authors":"L. A. Trujillo, J. Santos, Nuria Calero, M. C. Alfaro, José Muñoz","doi":"10.13140/2.1.2364.2244","DOIUrl":"https://doi.org/10.13140/2.1.2364.2244","url":null,"abstract":"Se estudian las propiedades reologicas de una suspoemulsion comercial para uso agroquimico. Se comparan los resultados obtenidos mediante curvas de flujo y ensayos en cizalla oscilatoria de baja amplitud para cinco temperaturas distintas en el intervalo de 5 a 25oC. Las curvas de flujo, ponen de manifiesto que la suspoemulsion se caracteriza por presentar un comportamiento pseudoplastico, menos acusado a medida que aumenta la temperatura, que se ajusta al modelo de Sisko. Barridos de esfuerzo realizados a 0,1Hz permiten determinar el reducido rango viscoelastico lineal de la suspoemulsion, que depende de la temperatura. Los espectros mecanicos, entre 3Hzy 0,01 Hz, revelan que el sistema manifiesta propiedades viscoelasticas con un comportamiento tipico de gel debil. La aparicion de un minimo en el valor de G” respecto a la frecuencia ha permitido estimar el modulo plateau, el cual desciende con el aumento de temperatura segun una ecuacion tipo Arrhenius. Aun asi, la suspoemulsion presenta un caracter elastico que favorece su estabilidad fisica con el tiempo de almacenamiento. Se ha demostrado ademas que el sistema no sigue la regla de Cox-Merz.","PeriodicalId":7709,"journal":{"name":"Afinidad","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66244072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Synthesis of some new 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives 新的4,5-二氢-6-(4-甲氧基-3-甲基苯基)-3(2H)-吡嗪酮衍生物的合成

IF 0.3 4区化学

Afinidad Pub Date : 2011-04-20 DOI: 10.5012/JKCS.2011.55.2.230

M. Soliman, S. El-Sakka

{"title":"Synthesis of some new 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives","authors":"M. Soliman, S. El-Sakka","doi":"10.5012/JKCS.2011.55.2.230","DOIUrl":"https://doi.org/10.5012/JKCS.2011.55.2.230","url":null,"abstract":"The present study describes the synthesis of 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives. The synthesis of the first target compound, 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone(1), was achieved by Friedel-Crafts acylation of o-cresylmethyl ether with succinic anhydride and subsequent cyclization of the intermediary g-keto acid with hydrazine hydrate. Condensation compound 1 with aromatical dehydes in the presence of sodium ethoxide affords the corresponding 4-substituted benzyl pyridazinones(3a-d). The pyridazinone 1 under went dehydrogenation upon treatment with bromine/acetic acid mixture to give (4). Pyridazine (5) has been synthesized upon the reaction of pyridazinone (1) with 1,3-diphenyl-2-propen-1-one under the Michael addition reaction. N-dialkylaminomethyl derivatives 6a-b have been obtained from the reaction of pyridazinone 1 with formaldehyde and secondary amine, whereas reaction of 1 with formaldehyde gives N-hydroxymethyl derivative (7). This study also includes the synthesis of the 3-chloro pyridazinone derivative 8 in excellent yield by heating pyridazinone 3b in phosphorus oxychloride. The behaviour of the chloro derivative toward sodium azide, benzyl amine and anthranilic acid was also studied. The proposed structures of the products were confirmed by elemental analysis, spectral data and chemical evidence.","PeriodicalId":7709,"journal":{"name":"Afinidad","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2011-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70592430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

EXPRESIÓN EN SISTEMAS FLUIDO-SÓLIDO NO CATALÍTICOS, CONTROLADOS POR LA DIFUSIÓN INTERNA EN PARTÍCULAS DE TAMAÑO FIJO. SEGUNDA PARTE 在非催化流体-固体体系中表达，由固定粒径的内部扩散控制。第二部分

IF 0.3 4区化学

Afinidad Pub Date : 2010-01-01 DOI: 10.1590/2224-6185.2010.3.%X

René Viera Bertrán, D. Álvarez, A. P. Hernández

{"title":"EXPRESIÓN EN SISTEMAS FLUIDO-SÓLIDO NO CATALÍTICOS, CONTROLADOS POR LA DIFUSIÓN INTERNA EN PARTÍCULAS DE TAMAÑO FIJO. SEGUNDA PARTE","authors":"René Viera Bertrán, D. Álvarez, A. P. Hernández","doi":"10.1590/2224-6185.2010.3.%X","DOIUrl":"https://doi.org/10.1590/2224-6185.2010.3.%X","url":null,"abstract":"En este trabajo se presento un modelo tipo caja negra que proporcionaba una relacion explicita entre la fraccion del reactante solido no convertido I; y la relacion Y = t/τ. Ademas, se presento un conjunto de aplicaciones posibles, para sistemas con flujo en piston para la fase solida. Se deducen las expresiones correspondientes a situaciones de mayor complejidad, tales como: reactores con mezclado perfecto para la fase solida, las cuales se tratan en las situaciones siguientes: Un solo reactor con tiempo de residencia medio: tp; particulas de un solo tamano; mezcla de particulas de diferentes tamanos; para dos reactores con tiempos de residencia medio Iguales (tp); para tres reactores con tiempos de residencia medio Iguales (tp); para cuatro reactores con tiempos de residencia medio Iguales (tp); para cinco reactores con tiempos de residencia medio Iguales (tp). El procedimiento empleado en las deducciones, puede ser utilizado en otras situaciones de interes sin mayores dificultades. Las expresiones presentadas, ademas de su facilidad de uso, presentan la ventaja de facilitar la confeccion de algoritmos programables. Palabras clave: paso controlante, difusion interna, fluido- solido no catalitico. In the first part of this paper, a black box model that provided an explicit relationship between the fraction of unconverted solid reactant I and the relationship Y = t /τ. You had a set of possible applications, for systems with plug flow for the solid phase. In this second part of the work, we deduce the expressions for more complex situations, such as perfect mixing reactor to the solid phase, which are discussed in the situations described below: a single reactor mean residence time: tp; particles of one size; mixture of particles of different sizes; for two reactors with residence times equal means (tp); for three reactors with residence times equal means (tp); for four reactors with residence times equal means (tp); for five reactor residence times equal means (tp)","PeriodicalId":7709,"journal":{"name":"Afinidad","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67306878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Utility of N-2-pyridyl-3-oxobutanamide in heterocyclic synthesis: Synthesis of new dihydropyridine, fused pyridine, pyridopyridine, pyridazine and pyridopyrimidinethione derivatives n -2-吡啶-3-氧丁烷酰胺在杂环合成中的应用:新型二氢吡啶、融合吡啶、吡啶吡啶、吡啶嗪和吡啶嘧啶硫酮衍生物的合成

IF 0.3 4区化学

Afinidad Pub Date : 2008-12-01 DOI: 10.21608/ABSB.2008.10502

I. S. A. Hafiz, S. Baker, A. Hussein

{"title":"Utility of N-2-pyridyl-3-oxobutanamide in heterocyclic synthesis: Synthesis of new dihydropyridine, fused pyridine, pyridopyridine, pyridazine and pyridopyrimidinethione derivatives","authors":"I. S. A. Hafiz, S. Baker, A. Hussein","doi":"10.21608/ABSB.2008.10502","DOIUrl":"https://doi.org/10.21608/ABSB.2008.10502","url":null,"abstract":"2-Aminopyridine was fused with ethyl acetoacetate without solvent for two hours to yield the N-2-pyridyl–3-oxobutanamide 1. However, when the reaction time was increased to 5 hours a structure 3 was obtained. Condensation of the structure 3 with benzaldehyde gave 4. The reaction of pyridopyridone 3 with arylidenemalononitrile7a-c afforded 4 H-pyran derivative 10a-c. In contrast to the behavior of arylidenemalononitrile 7a-c towards pyridopyridine3, benzylidenemalononitrile 7d reacted withcompound 3 to give a product 11. Compound 1 was allowed to react with arylidenemalononitrile to give the dihydropyridine derivative 17a-d. Alkylation of compound 1 with alkylating agents has been also reported. Thus, compound 1 was condensed with [DMF-DMA] in refluxing dioxane to yield 18, but under the reaction conditions we obtained only 21. The pyridopyridone 3 reacted with benzoylisothiocyanate 25a,b to give thiourea derivatives 26a,b Cyclization of 26a,b in dry dioxane and conc. sulphuric acid afforded pyridopyrimidinethione derivatives 27a,b. On the other hand, coupling of pyridopyridine 3 with the aromatic diazonium salt 28a-e afforded the corresponding azo products 29a-e. Boiling of compound 29 in aqueous solution of HCl afforded the hydrazo products 30. Treatmentof arylhydrazone 30a with malononitrile afforded the pyridazine derivatives 31.","PeriodicalId":7709,"journal":{"name":"Afinidad","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68374869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of some new spiropyrazolo[4',5':5,6]-pyrano[2,3-d]pyrimidines 一些新的螺吡唑[4′，5′:5,6]-吡喃[2,3-d]嘧啶的合成

IF 0.3 4区化学

Afinidad Pub Date : 2000-03-01 DOI: 10.3987/COM-99-8797

M. Al-Thebeiti

引用次数: 4

Afinidad最新文献