0000000000172093
AUTHOR
Carla Boga
showing 3 related works from this author
Mononuclear Rearrangement of the Z-Phenylhydrazones of Some 3-Acyl-1,2,4-oxadiazoles: Effect of Substituents on the Nucleophilic Character of the >…
2019
The reaction rates for the mononuclear rearrangement of the Z-phenylhydrazones of 3-acyl-1,2,4-oxadiazoles 3a-c into the relevant 2-phenyl-2 H-1,2,3-triazoles (4a-c) have been measured in dioxane/water at different temperatures in a large range of proton concentrations. The occurrence of two different reaction pathways (one uncatalyzed, water assisted, and the other general base catalyzed) has- been observed. The obtained results have been able to furnish information about the effects of the nature of the 3-acyl structure and of the 5-substituents in the 1,2,4-oxadiazole ring on the reactivity of the examined rearrangements: they are well in line with the previsions carried out considering …
Electron Ionization Induced Fragmentation of some 3-Aroylamino-5-Methyl-1,2,4- Oxadiazoles and 3-Acetylamino-5-Aryl-1,2,4-Oxadiazoles
2017
: Background and objectives. 1,2,4-Oxadiazoles show a high reactivity and represent starting compounds for the synthesis of several other heterocycles. Some their derivatives can give the so called Boulton-Katritzky Reactions (BKR) which opens the way to the synthesis of several azoles. For this reason we have registered the mass spectra of several 3-aroylamino-5-methyl-1,2,4-oxadiazoles and 3-acetylamino-5-aryl-1,2,4-oxadiazoles. Methods and results. Thus, studying the mass spectra of the isomeric couple 3-benzoylamino-5-methyl-1,2,4-oxadiazole (1A) and 3-acetylamino-5-phenyl-1,2,4-oxadiazoles (1B) we have observed that MIKE and CID MIKE spectra of their molecular ions and of the [M – CH2C…
On the Nucleophilic Reactivity of 4,6-Dichloro-5-nitrobenzofuroxan with Some Aliphatic and Aromatic Amines: Selective nucleophilic substitution
2020
The reaction rates for the nucleophilic aromatic substitution of 4,6-dichloro-5-nitrobenzofuroxan 1 with eight aliphatic amines (characterized by very different basicities/ nucleophilicities) and three anilines have been measured in both methanol and toluene. The obtained rates have been related to the basicity (pKaH in water and Kb in benzene) or nucleophilicity (N Mayr constants) of the tested amines. The whole of the obtained kinetic data has furnished useful information on the high nucleophilic reactivity of benzofuroxan derivatives, which has been related essentially to two factors: the high electron-drawing ability/power of the condensed furoxan ring and the low aromatic character of …