31709-19-0Relevant articles and documents
The ionic liquid effect on the Boulton-Katritzky reaction: a comparison between substrates of different structure
D'Anna, Francesca,Millan, Daniela,Noto, Renato
, p. 7361 - 7366 (2015)
Abstract The mononuclear rearrangement of heterocycles, also called Boulton-Katritzky reaction, was studied in ionic liquid solution using N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-(4-nitrophenyl)-formamidine as substrate. The investigation was carried out using piperidine as basic catalyst and several ionic liquids differing in both cation and anion structure. Kinetic data collected were compared with the ones previously reported using (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole to have information about the effect due to the different structure of the alkyl chain borne on the substrate. Furthermore, data were analysed on the grounds of polarity, Kamlet-Taft solvent parameters, but taking also in consideration the structural features of the solvent used. On the whole, the results obtained seem to indicate that the 'ionic liquid effect' can be explained considering the structural features of the constituent ions, their effect on the structure of solvent media and their ability to interact with the transition state of the target reaction.
Mononuclear Heterocyclic Rearrangements. Effect of the Structure of the Side Chain on the Reactivity. Part 3. Rearrangement of Some N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-arylformamidines into 1-Aryl-3-benzoylamino-1,2,4-triazoles in Acetonitrile in the Presence of Triethylamine
Frenna, Vincenzo,Macaluso, Gabriella,Vivona, Nicolo,Spinelli, Domenico,Consiglio, Giovanni,Mezzina, Elisabetta
, p. 7315 - 7326 (2007/10/02)
The apparent pseudo-first-order rate constants for the title reaction give a curvilinear plot versus tertiary amine concentration, according to the equation kA=(ku+K1k2)/(1+K1).This shows the occurrence of two different reaction pathways; the one, independent of and the other, dependent on , which involves a fast conversion of the substrate into an acid-base adduct or an ion pair followed by its slow conversion into the corresponding triazole.The substituent effects on these reactions have also been studied.
Mononuclear Heterocyclic Rearrangements. Effect of the Structure of the Side Chain on the Reactivity. Part 2. Rearrangement of Some N-(5-Phenyl-1,2,4-oxadiazol-3-yl)-N'-arylformamidines into 1-Aryl-3-benzoylamino-1,2,4-triazoles in Dioxane-Water at Various pS+
Frenna, Vinzenzo,Vivona, Nicolo,Consiglio, Giovanni,Spinelli, Domenico,Mezzina, Elisabetta
, p. 1339 - 1343 (2007/10/02)
In the framework of studies concerning the effect of the structure of the side chain mechanism and the reactivity in mononuclear heterocyclic rearrangements, the reactivity of some N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-arylformamidines 3 in dioxane-water in the pS+-range 6.0-15.0 was studied and compared with that of arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole 7 and of 3-arylureido-5-phenyl-1,2,4-oxadiazoles 5.A plot of the logarithms of the rate constants versus pS+ showed the occurrence of an uncatalysed (pS+ -independent) and of a catalysed (pS+ -dependent and then pS+ -independent) range.Kinetic data pointed out that the base catalysis is specific, in accord with the relatively high acidity of the formamidines used.The substituent effects on the reactivity were compared with those observed in other mononuclear heterocyclic rearrangements.
