12 documents found, page 1 of 2
The reaction of 1,2-Dichloro-4,5-dinitrobenzene with hydroxide ion: roles of me...
Blaskó,Andrei; Bunton,Clifford A.; Gillitt,Nichollas D.; Bacaloglu,Radu; Yunes,Santiago F.; Zucco,CésarThe reaction of 1,2-dichloro-4,5-dinitrobenzene (DCDNB) with aqueous OH- produces (after acidification) 2-nitro-4,5-dichlorophenol with loss of NO2. Nevertheless, with > 2 mol L-1 OH-, only DCDNB was recovered due to the formation of the long-lived 3,6-dihydroxy Meisenheimer complex (M2-), and that in acid, reverted to the starting material. Fast formation of monohydroxy Meisenheimer complex (M1-) can be follow...
Química sem fronteiras
Pinto,Angelo C.; Zucco,César; Galembeck,Fernando; Andrade,Jailson B. de; Vieira,Paulo C.The main objective of this paper is to start and stimulate reflection, discussion and proposing actions that allow Chemistry in Brazil contribute to a prosperous, safer and better future for the nation.
Recentes aplicações sintéticas de compostos orgânicos tricloro(bromo)metila sub...
Menezes,Fabrício Gava; Gallardo,Hugo; Zucco,CésarThis review presents the recent applications of some trihalomethyl carbinols, α,α,α-trihalogenated carbonyl compounds and trichloro(bromo)methyl-containing heterocycles, acting as high versatile synthetic precursors in organic chemistry, based on the last 10 years' literature.
Graduação em química: avaliação, perspectivas e desafios
Zucco,CésarPoor standards in schools and the increase in the number of institutions of higher education - frequently without the due control - have adversely affected the quality of university level education in Brazil. On the other hand, evaluation of undergraduate courses, which has been carried out regularly since the min 1990's allow, within certain limits, a description of the quality Brazilian higher education cours...
Reações de 1,2-dicloro-4,5-dinitrobenzeno com aminas: monossubstituição de nitr...
Menezes,Fabrício Gava; Ricardo,Juan; Dias,Rafael; Bortoluzzi,Adailton J.; Zucco,César1,2-dichloro-4,5-dinitrobenzene (DCDNB) reacts with primary and secondary amines, in acetonitrile, at room temperature, to give a monosubstituted nitro product with a yield of 85 to 95%. The chloro-nitro-disubstituted product is formed with excess amine under reflux. Piperidine, pyrroline, dimethylamine and methylamine were the most reactive reagents in both mono- and disubstitution.
Química no Brasil: perspectivas e necessidades para a próxima década - Document...
Andrade,Jailson B. de; Pinto,Angelo C.; Cadore,Solange; Vieira,Paulo Cezar; Zucco,César; Pardini,Vera L.; Curi,Luiz Roberto LizaOver the past years the Brazilian Chemical Society (SBQ) has been working on different projects related to the development of Chemistry in Brazil. After a discussion throughout the country two documents have been published in Quimica Nova: "Mobilizing Axes in Chemistry" and "The Chemist's Education". Here, we describe the initial document which was the starting point for the discussion of a new series of papers...
A graduação em química: um novo químico para uma nova era
Zucco,CésarThe discussions sponsored by the Brazilian Chemical Society, over the past five years, intending to produce a chemistry agenda with perspectives and needs for the next decade for the country, have involved the national chemistry community and several related sectors of Brazilian society. Chemistry education has been the theme throughout these discussions. It is known that the low level of basic and secondary ed...
A formação do Químico
Andrade,Jailson B. de; Cadore,Solange; Vieira,Paulo Cezar; Zucco,César; Pinto,Angelo C.Training of highly qualified personnel is the most transversal axis among those identified in the document "Mobilizing Axes in Chemistry", published by SBQ, in 2002, which demands to deep the discussions, initiated in the symposium "The Chemist's Education", whose main objective was to discuss the repercussions of that training in the teaching and in the industrial section. After the publication of an initial p...
Eixos mobilizadores em química
Andrade,Jailson B. de; Cadore,Solange; Vieira,Paulo C.; Zucco,César; Pinto,Ângelo C.Over the last five years there have been significant changes in higher education in Brazil as well as in research funding. As a contribution to the development of Science and Technology, and aiming to portray Chemistry today in Brazil, in the context of last year´s elections for President, State Governors, National Congress and Legislative Chamber, the Directors and Consulting Council of the Brazilian Chemical ...
The Influence of Substituents on the Tautomerism of Symmetrically Substituted 2...
Dall'Oglio,Evandro; Caro,Miguel B.; Gesser,José C.; Zucco,César; Rezende,Marcos C.The tautomerism of five symmetrically substituted 2,2'-bis-benzimidazoles [5(6),5'(6')-tetramethyl- (1); 5(6),5'(6')-dimethyl-(2); 5(6),5'(6')-dichloro- (3); 5(6),5'(6')-dimethoxy- (4) and 4(7),4'(7')-dimethyl-2,2'-bis-benzimidazole (5)], was studied by means of ¹H NMR spectroscopy at variable temperatures, and the influence of the substituents on the energy barriers for tautomeric interconversion was interpret...