| Autor: |
D'ANNA, Francesca, FRENNA, Vincenzo, MACALUSO, Gabriella, MARULLO, Salvatore, GUERNELLI S, LANZA C, SPINELLI, D. |
| Přispěvatelé: |
D'ANNA F, FRENNA V, GUERNELLI S, LANZA C, MACALUSO G, MARULLO S, SPINELLI |
| Jazyk: |
angličtina |
| Rok vydání: |
2009 |
| Předmět: |
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| Popis: |
To select suitable candidates for the occurrence of specific-base-catalysis in MRH of (Z)-hydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole we have designed a modification of the side-chain structure by linking a strong electron-withdrawing system to the hydrazono group. Thus we have synthesized the (Z)-semicarbazone (3d), the (Z)-phenylsemicarbazone (3e), and the (Z)-acetylhydrazone (3f) of the above oxadiazole and examined their kinetic behavior in dioxane/water in a large range of proton concentrations (pS + 4.0 14.5). In all the pS+ range examined only a base-catalyzed process has been evidenced (no uncatalysed path occurs). The behavior at the largest pS+ values (the reactivity tends to a limiting rate constant) and that at variable concentrations of buffer have furnished clear evidence for the occurrence of a specificbase- catalysed process, thus reaching the target proposed and confirming the prevision. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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