The effect of an electron-withdrawing group in the imidazolium cation: the case of nitro-functionalized imidazolium salts as acidic catalysts for the acetylation of glycerol was written by Morais, Eduardo M.;Grillo, Igor B.;Stassen, Hubert K.;Seferin, Marcus;Scholten, Jackson D.. And the article was included in New Journal of Chemistry in 2018.COA of Formula: C4H5N3O2 This article mentions the following:
The acetylation of glycerol was achieved with high conversion and selectivity towards triacetin at low temperatures and short reaction times by using acidic imidazolium salts as catalysts. Moreover, the addition of a nitro group to the imidazolium cation affords a much more competent catalyst, indicating a significant effect provided by the simple electronic change in the imidazolium cation. Theor. calculations revealed increased polarization of the acidic hydrogen bond on the nitrated salts, which may be related to their superior catalytic behavior when compared to the non-functionalized salts. Combining the preliminary exptl. and theor. results, it is possible to suppose that the catalytic activity of acidic imidazolium salts may be better comprehended by its Bronsted acidities, but other parameters such as hardness, electronegativity, electrophilicity and ion-pair binding energy were also evaluated in order to investigate their effects in the acetylation of glycerol promoted by these acidic imidazolium salts. In the experiment, the researchers used many compounds, for example, 1-Methyl-4-nitroimidazole (cas: 3034-41-1COA of Formula: C4H5N3O2).
1-Methyl-4-nitroimidazole (cas: 3034-41-1) belongs to imidazole derivatives. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. The pharmacophore of imidazole exists in bioactive compounds including amino acids, plant growth regulators and therapeutic agents.n increase of the alkyl chain length of the alcohols. COA of Formula: C4H5N3O2
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem