Versatile and Scalable Method for Producing N-Functionalized Imidazoles

Abstract

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.

N‐Heterocyclic Olefin–Carbon Dioxide and –Sulfur Dioxide Adducts: Structures and Interesting Reactivity Patterns

“…All solvents were dried according to common procedures and passed through columns of aluminium oxide, 3 Å molecular sieves, and R3‐11G‐catalyst (BASF) or stored over molecular sieves (3 or 4 Å) until use. 1‐Ethyl‐2‐methylimidazole was prepared according to a published general procedure for the alkylation of imidazoles . As the sodium salt of 2‐methylimidazole reacted violently with ethyl bromide if following the original specifications, the sodium imidazolate was suspended in twice the recommended volume of THF and ethyl bromide was then added dropwise at 0 °C before warming to room temperature.…”

“…1-Ethyl-2-methylimidazole was prepared according to ap ublished general procedure for the alkylation of imidazoles. [56] As the sodium salt of 2-methylimidazole reacted violently with ethyl bromide if following the original specifications, the sodium imidazolate was suspended in twice the recommended volume of THF and ethyl bromide was then added dropwise at 0 8Cbefore warming to room temperature.…”

Chemical and Physical Absorption of SO2 by N-Functionalized Imidazoles: Experimental Results and Molecular-level Insight

“…We have previously shown that a variety of imidazoles with electron donating groups can be readily synthesized at reasonably large scales with simple chemical reactions using inexpensive starting materials. 49,50 Here we focus on as series of 11 imidazole solvents with electron-donating groups attached to the imidazole ring at the C(2), C(4) and/or C(5) positions ( Figure 1) and the impact of substitutions on the binding strength of SO 2 −imidazole complexes.…”

Recent advances in the synthesis and applications of metal organic frameworks doped with ionic liquids for CO 2 adsorption

“…ILs can be synthesized via several different mechanisms [63] from a variety of starting materials and have a great deal of possible structural variation afforded by selection of "R" group(s) (Fig. 4).…”