Acid- and Base-Catalysis in the Mononuclear Rearrangement of Some (Z)-Arylhydrazones of 5-Amino-3-benzoyl-1,2,4-oxadiazole in Toluene: Effect of Substituents on the Course of Reaction

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• 作者：Francesca D鈥橝nna ; Vincenzo Frenna ; Franco Ghelfi ; Salvatore Marullo ; Domenico Spinelli
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：April 15, 2011
• 年：2011
• 卷：76
• 期：8
• 页码：2672-2679
• 全文大小：914K
• 年卷期：v.76,no.8(April 15, 2011)
• ISSN：1520-6904

文摘

The reaction rates for the rearrangement of eleven (Z)-arylhydrazones of 5-amino-3-benzoyl-1,2,4-oxadiazole 3a鈭?b>k into the relevant (2-aryl-5-phenyl-2H-1,2,3-triazol-4-yl)ureas 4a鈭?b>k in the presence of trichloroacetic acid or of piperidine have been determined in toluene at 313.1 K. The results have been related to the effect of the aryl substituent by using Hammett and/or Ingold鈭扽ukawa鈭扵suno correlations and have been compared with those previously collected in a protic polar solvent (dioxane/water) as well as with those on the analogous rearrangement of the corresponding (Z)-arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole 1a鈭?b>k in benzene. Some light can thus be shed on the general differences of chemical reactivity between protic polar (or dipolar aprotic) and apolar solvents.