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51.
The rates of base-catalyzed hydrogen-deuterium exchange at C-2 in some 5-substituted benzothiazoles and in thiazolo[4,5-c]pyridine were studied. Transmission through the thiazole ring of the effects of substituents in the benzothiazoles and of the polar effects of the aza group in the thiazolopyridine, was assessed from these data.  相似文献   
52.
A mild, simple and convenient method for the synthesis of some 1-(arylamino)pyrrole derivatives by copper(II) ion-catalyzed reaction of (arylazo)alkenes and 1, 3-dicarbonyl compounds is reported. These reactions take place under magnetic stirring at room temperature, do not require a strong acid or base, nor expensive or difficultly available reagents, nor even complicated procedures. The synthesis seems to be successfully applicable to different (arylazo)alkenes, 1, 3-diketones and ß-ketoesters, and frequently occurs with good yields.  相似文献   
53.
Aliphatic tosylhydrazides upon treatment with diborane followed by alkaline hydrolysis yield aliphatic hydrocarbons. Aromatic hydrocarbons are produced when aromatic tosylhydrazides undergo heating in presence of diborane and are subsequently oxidated by KIO4. A discussion on the structures of intermediate products is reported.  相似文献   
54.
Photochemical and anionic polymerizations of 1,2-diaza-1,3-butadienes are described. Photochemical polymerization was smoothly performed by irradiation of some 1-aminocarbonyl-1,2-diaza-1,3-butadienes with high pressure mercury arc (λ = 300 nm) in the presence of allyltributylstannane. Molecular weights (Mw) in the range 14.6-559 × 102 g/mol were obtained. The TGA curve revealed a first weight loss starting at about 200 °C of some 85%, and a second starting at about 300 °C. The DSC showed the glass transition (Tg) at about −34 °C. Anionic polymerization was performed by treatment of some 1-alkoxycarbonyl-1,2-diaza-1,3-butadienes with n-butyllithium. Molecular weights (Mw) in the range 8.44-242 × 102 g/mol were obtained.  相似文献   
55.
By highly efficient, one-pot, three-component reactions, combining one set of 1,2-diaza-1,3-dienes (DDs), primary amines, and isothiocyanates in a different sequential order of addition, heterocyclic skeletal diversity can be achieved. The key feature discriminating the different heterocyclic core formation is the availability of the N or S heteronucleophile to give the first Michael addition step affording regioselective substituted 2-thiohydantoins or 2-iminothiazolidinones. The hydrazone or enehydrazino side chain at the 5-position of both heterocycles represents a valuable functionality to reach novel 5-hydroxyethylidene derivatives difficult to obtain by other methods.  相似文献   
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