Abstract
The syntheses of two perdeuterated ionic liquids (ILs), which have found use as solvents for cellulose derivatization and processing in addition, are described: 1‐ethyl‐3‐methylimidazolium acetate (EMIM‐OAc‐d~14~) and 1‐butyl–3‐methylimidazolium acetate (BMIM‐OAc‐d~18~). The targets were obtained from imidazole in three‐step sequences starting with butylation and ethylation, respectively. The resulting 1‐alkyl imidazoles were purified, and subsequently methylated according to a novel protocol using dimethylcarbonate‐d~6~. To obtain the 1‐alkyl‐3‐methylimidazolium moiety, methylation of 1‐alkylimidazoles proved to be superior to the conventional approach of alkylating 1‐methylimidazole. Addition of acetic acid‐d~4~ caused traceless degradation of the methylcarbonate counter anions, which were neatly exchanged for acetate. The IL 2‐^13^C‐butyl‐3‐methylimidazolium acetate, in which the isotopically enriched C‐2 is a good NMR‐indicator of side reactions and solvent–solute interactions, was synthesized according to the same reaction sequence, starting from 2‐^13^C‐1‐alkylimidazole which, in turn, was obtained by reaction of glyoxale, alkylamine, ammonia and paraformaldehyde‐^13^C. Copyright © 2009 John Wiley & Sons, Ltd.