One of the main directions of world research is the search for chemical compounds with special properties. Ionic liquids are such compounds. Their use opens up new possibilities for modern chemical technology. Ionic liquids perfectly fit into the assumptions of green chemistry. Contrary to the current approach, green chemistry requires the design, development and introduction of new processes and chemicals to reduce or eliminate the use and production of hazardous substances. The method of carrying out these tasks is described by the twelve principles of green chemistry, formulated in 1998 by Anastas and Warner. Ionic liquids meet at least three of these principles, i.e. the principle 5 (as safer solvents), 6 (they allow for efficient use of energy) and 9 (they are used in catalytic reactions). The precursors of ionic liquids are quaternary ammonium halides, known since the 1990s, widely researched and used in the 20th century.
