- ALKYLATION OF AZOLES USING beta -FUNCTIONAL ALKYL HALIDES UNDER CONDITIONS OF PHASE TRANSFER CATALYSIS.
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The objective of this study was to develop a convenient synthetic method for direct N-alkylation of pyrazole (I), 3(5)-methylpyrazole (II), 3,5-dimethylpyrazole (III), 1,2,4-triazole (IV), and tetrazole (V) using beta -functional alkyl halides under conditions of two-phase catalysis and with high product yields. This investigation was stimulated by the fact that the desired reaction products are intermediates in the synthesis of an important class of compounds, vinylazole, as well as of various pharmaceutical agents. It is found that depending on the acidity of the azole, alkylation with dichloroethane can be accompanied by beta -elimination. The effect of solvent on the course of alkylation reactions using dichloroethane has also been studied, and revealed that the reactions occur via the intermediacy of ion pairs rather than free anions.
- Asratyan,Attaryan,Pogosyan,Eliazyan,Darbinyan,Matsoyan
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p. 1202 - 1206
(2007/10/02)
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