The effect of ultrasound on the N-alkylation of imidazole over alkaline carbons: Kinetic aspects

Ferrera-Escudero, S.; Perozo-Rondón, E.; Casilda, Vanesa Calvino; Casal, Blanca; Martı́n-Aranda, R.M.; López-Peinado, A.J.; Durán‐Valle, Carlos J.

doi:10.1016/j.apcata.2010.01.041

Cited by 15 publications

(5 citation statements)

References 14 publications

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“…Because N -functionalized imidazoles and bis(imidazoles) have very low vapor pressures and high boiling points themselves, distillation of the final product can be very difficult or virtually impossible in many cases. Unconventional approaches to the synthesis of N -functionalized imidazoles have made use of ultrasound − or microwaves − with catalysts with varying degrees of success at small scales.…”

Section: Introductionmentioning

confidence: 99%

Versatile and Scalable Method for Producing N-Functionalized Imidazoles

Bara

2011

Ind. Eng. Chem. Res.

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Imidazolate salts are powerful and versatile starting materials that can be used to generate many useful compounds. To this end, a method for producing sodium imidazolate (NaIm) from only commodity starting materials has been developed. NaIm was directly produced at a scale of ∼400 g via the neutralization of molten imidazole by NaOH, followed by dehydration. The NaIm product was then utilized as a starting material to produce 20 different N-functionalized imidazole and bis(imidazole) compounds, with the application of a common procedure involving minimal solvent volumes and straightforward purification via flash chromatography and solvent evaporation. Generating N-functionalized imidazoles "on demand" from NaIm and alkyl halides (or similar compounds) can eliminate the need for hazardous starting materials such as NaH and anhydrous solvents that have typically been employed in their synthesis. This method may ultimately enhance the availability of N-functionalized imidazoles for a variety of research and commercial applications.

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Section: Introductionmentioning

confidence: 99%

Versatile and Scalable Method for Producing N-Functionalized Imidazoles

Bara

2011

Ind. Eng. Chem. Res.

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“…of carbon treated with alkali metal salts. This treatment has been described to increase the basicity of other carbons, mainly if a potassium salt is used [33].…”

Section: Acidic and Basic Propertiesmentioning

confidence: 99%

“…In this work, carbon xerogels were prepared by modifying a mesoporous carbon surface chemically with concentrated mineral acids and the adsorption of alkali metal chlorides. These treatments were carried out in our laboratory to obtain acid catalysts [31] or basic catalysts [32,33] on activated carbons. However, we have not tested them on xerogels often, but, when we have done so, we have used them as catalysts [34].…”

Section: Introductionmentioning

confidence: 99%

Unlocking the Potential of Chemically Modified Carbon Gels in Gallic Acid Adsorption

Carvalho,

Durán-Valle,

Adame-Pereira

2024

Gels

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This study deals with the preparation of adsorbents from a commercial xerogel by chemically modifying its surface with concentrated mineral acids and alkali metal chlorides, their physicochemical characterization, and their use as adsorbents for gallic acid in aqueous solution. Although there are publications on the use of carbon xerogels as adsorbents, we propose and study simple modifications that can change their chemical properties and, therefore, their performance as adsorbents. The adsorbate of choice is gallic acid and, to our knowledge, there is no history of its adsorption with carbon xerogels. The prepared adsorbents have a high specific surface area (347–563 m2 g−1), better pore development for samples treated with alkali metal chlorides than with mineral acids, and are more acidic than the initial xerogel (p.z.c range 2.49–6.87 vs. 7.20). The adsorption equilibrium is reached in <16 h with a kinetic constant between 0.018 and 0.035 h−1 for the pseudo-second-order model. The adsorption capacity, according to the Langmuir model, reaches 62.89 to 83.33 mg g−1. The adsorption properties of the commercial xerogel improved over a wide range of pH values and temperatures. The experimental results indicate that the adsorption process is thermodynamically favored.

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“…Martín-Aranda and coworkers reported that alkaline carbons (Na-Norit, Cs-Norit, and NaCs-Norit among others) are appropriate solids to catalyze selectively, and with almost total yields, the N-alkylation of imidazole with propargyl bromide or 1-bromobutane under microwave (MW) and ultrasound activation [100][101][102]. ACs have been broadly used to catalyze organic synthesis due to their extended surface area, microporosity, and high degree of surface reactivity.…”

Section: Alkylation Reactions Of Imidazole and Related Compoundsmentioning

confidence: 99%