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Synthesis of the perdeuterated cellulose solvents 1‐ethyl‐3‐methylimidazolium acetate (EMIM‐OAc‐d 14 ) and 1‐butyl‐3‐methylimidazolium acetate (BMIM‐OAc‐d 18 ) and of 2‐ 13 C‐butyl‐3‐methylimidazolium acetate
Author(s) -
Yoneda Yuko,
Ebner Gerald,
Takano Toshiyuki,
Nakatsubo Fumiaki,
Potthast Antje,
Rosenau Thomas
Publication year - 2009
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.1591
Subject(s) - chemistry , ionic liquid , moiety , acetic acid , alkyl , imidazole , ammonium acetate , ammonia , solvent , butyl acetate , ethyl acetate , medicinal chemistry , paraformaldehyde , organic chemistry , catalysis , high performance liquid chromatography
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.