A solution of 1,4,5-triphenyl-2-(7-bromoheptyloxy)-imidazole (2.0 g) in ethanol (10 ml) was refiuxed with a solution of sodium sulphite (0.55 g) in water (5 ml) for 20 hours. More sodi,,m sulphite (0.2 g) in water (1 ml) was added and refiuxed a further 20 hours. The mixture was evaporated to dryness, boiling ethanol added and filtered hot. Chromatography of the flitrate on silica gel (dichloromethane/methanol 5:1) followed by crystallisation from ethanol/isopropanol gave sodium 7-(1,4,5-triphenylimidazol-2-yloxy)heptanesulphonate (0.3 g, 15%) as a colourless solid, m.p. 246-8° C. Found: C, 64.47; H, 5.85; N, 5.09; S, 5.50%; C28H29N2Na04S +2% isopropanol +2% water; Requires: C, 64.19; H, 5.96; N, 5.25; S, 6.01%.
