A series of 1,2-dimethyl-3-arylsulfonyl1-4,5-dihydroimidazolium iodides (7–11) was prepared by convenient sulfonylation and methylation from commercially available 2-methyl-2-imidazoline. Trisubstituted ethylenediamine derivatives 12–21 were synthesized from the reduction or hydrolysis of imidazolium salts 7–11 in high yield.