Syntheses and Studies on New Dual Functionalized Zwitterions and Ionic Liquids - Imidazolium and 1,2,3-Triazolium based structures

The purpose of this master's project was to synthesize new dual functionalized non-toxic imidazolium based zwitterions (ZIs), and ionic liquids (ILs) with high cellulose dissolution potential. As well as new 1,5-disubstituted 1,2,3-triazoles and 1,3,5-trisubstituted 1,2,3-triazolium ILs. Metal-free approaches towards regioselective preparation of 1,5-disubstituted 1,2,3-triazoles are scarce, but recently a new synthetic route using readily available substrates has been presented. 1,5-Disubstituted 1,2,3-triazoles 2 and 3 were respectively prepared in 28 % and 59 % yield, by a metal-free synthesis using 4-nitrophenyl azide (1) as azide transfer reagent. 1-Benzyl-3-ethyl-5-phenyl-1,2,3-triazolium iodide (4a) was prepared in 66 % yield by quaternization of triazole 3. By anion exchange through Finkelstein reaction from IL 4a using silver acetate, IL 1-benzyl-3-ethyl-5-phenyl-1,2,3-triazolium acetate (4b) was prepared in 14 % yield. The toxicity of ILs for cellulose dissolution is a general problem when synthesized for industrial use. A new synthetic method of IL preparation through less toxic dual functionalized ZIs was used. The ZI intermediates 5a, 6a, 8a and 10a were synthesized by addition of ether substituents to imidazole through SN2 reactions. The ZIs 5b, 6b, 8b and 10b were synthesized from intermediates by addition of alkyl sulfate through nucleophilic attack and ring opening of 1,3-propanesultone in 91 %, 99 %, 93 % and 74 % yield, respectively. By protonation with sulfuric acid, phosphoric acid, trimethanesulfonic acid and methanesulfonic acid the ILs 5c-f, 6c-f, 8c-f and 10c-f were prepared in high yields