Ionic liquid as catalyst in the synthesis of N-alkyl trifluoromethyl pyrazoles

Frizzo, Clarissa P.; Moreira, Davidson Martins; Guarda, Emerson Adriano; Fiss, Gabriela F.; Marzari, Mara R. B.; Zanatta, Nilo; Bonacorso, Hélio G.; Martins, Marcos A. P.

doi:10.1016/j.catcom.2008.12.030

Cited by 18 publications

(8 citation statements)

References 22 publications

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“…Likewise during separations (extraction of products, for example) if aggregates are formed, both hydrophobic and hydrophilic compounds can be solubilized, thereby decreasing the effectiveness of the process [6]. Our own group has used ILs in organic synthesis [13][14][15], and we are interested to develop ILs that match satisfactory performance in organic synthesis. Thus, beyond the aforementioned properties of ILs, high miscibility with reactants, high diffusion, no aggregates formation, and low toxicity are desirable.…”

Section: Introductionmentioning

confidence: 98%

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Frizzo

Bender

Gindri³

et al. 2015

Colloid Polym Sci

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This work reports the study of the anion effect on the aggregation behavior of the long-chain spacers of dicationic imidazolium-based ionic liquids (ILs) in a 4.75 % (v/ v) ethanol-water solution as well as in ethanol (95 %). The anions studied were Br − , NO 3 − , BF 4 − , SCN − and NTf 2 − .Aggregation behavior was investigated by differential scanning calorimetry (DSC), conductivity, surface tension, and fluorescence. In the ethanol-water solution, the critical aggregation concentration (CAC), free energy aggregation (ΔG°a), and the ionization degree (α) all significantly decreased with the increase in anion hydrophobicity. In ethanol, the CAC and ΔG°a values also decreased with the increase in anion size and hydrophobicity. The free energy adsorption (ΔG°a ds ) data showed that the dicationic ILs have good surfactant activity, and this property improved with the decrease in the hydration radius of the anions. The anion volumes calculated also showed a good correlation with the CAC values for aggregation in ethanol-water solution and ethanol.

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Section: Introductionmentioning

confidence: 98%

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Frizzo

Bender

Gindri³

et al. 2015

Colloid Polym Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this way, it is clear the importance to develop a new methodology regarding this reaction. Our research group has previously reported the N-alkylation of pyrazoles using IL as solvent in oil bath [31]. Thus, we focused the use of efficient MW irradiation to perform the N-alkylation of pyrazoles in less polar solvents.…”

Section: Methodsmentioning

confidence: 99%

“…[BMIM] [BF 4 ] was selected due to its successful results in our previous work of N-alkylation in oil bath [31]. The amount of IL employed was ~ 0.1 mmol.mL -1 , which represents the minimum quantity required to achieve 150 °C in the four solvents under Ionic Liquids -New Aspects for the Futurestudy -HEX, TOL, THF and DIO (Figure 3) [66].…”

Section: Methodsmentioning

confidence: 99%

“…The amount of IL employed was ~ 0.1 mmol.mL -1 , which represents the minimum quantity required to achieve 150 °C in the four solvents under Ionic Liquids -New Aspects for the Futurestudy -HEX, TOL, THF and DIO (Figure 3) [66]. We also selected a base, KOH, to investigate the influence of basic catalysis on this reaction [31]. Initially, the reaction between butyl bromine and 3,5-dimethylpyrazole was performed in absence of basic catalysis.…”

Section: Methodsmentioning

confidence: 99%

“…Several studies have reported the application of ionic liquids (ILs) in different areas and, in particular, their use in organic reactions [25][26][27][28][29][30][31][32][33]. ILs are generally defined as liquid electro-lytes composed entirely of ions.…”

Section: Introductionmentioning

confidence: 99%

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