The concept of ionic liquids (ILs) has evolved significantly over the past 40 years. The considerable amount of data obtained from studies of compounds belonging to this group and the property models created from them have made it possible to verify early assertions about ILs, namely, that they are safe, nontoxic, thermally stable and "green" compounds, particularly in comparison to conventional organic solvents . When the potential problems of recycling and disposal of ILs are considered, as well as the effects of their introduction into the environment, the search for new sources of IL ions and safer methods for their synthesis becomes important .