BEt 2 (OSO 2 CH 3 ) was treated with 1-HOCPh 2 -2-NMe 2 C 6 H 4 (1) in the presence of acetic acid to give a red oily residue, which was separated by column chromatography into the two products [1-HOCPh 2 -2-NHMe 2 C 6 H 4 ][MeSO 3 ]·MeSO 3 H (2) and the known compound (BEt) 2 (μ-O)(μ-O,O′-O 2 CCH 3 ) 2 (3). Compound 2 was prepared independently from 1 and methylsulfonic acid. Compound 2 was characterized spectroscopically (NMR, IR) and by crystal structure determination. The latter shows the association of two ions and one molecule [1-HOCPh 2 -2-NHMe 2 C 6 H 4 ] + , [MeSO 3 ] − and MeSO 3 H by hydrogen bonding.