Phenyl sulphonyl isocyanate (1.2 g) was added to a suspension of 3-(4-carboxybenzyloxy) 2-(1-imidazolylmethyl)pyridine (1.0 g) in dry tetrahydrofuran (40 ml) containing triethylamine (0.33 g). The mixture was stirred at room temperature for 8 hours and allowed to stand at room temperature for a further 36 hours. The solvents were evaporated under vacuum and aqueous 5% sodium bicarbonate solution (100 ml) added to the residue. The mixture was extracted with dichloromethane (3×50 ml) and the combined organic extracts dried, filtered and evaporated to yield an oil which solidified on trituration with diethyl ether. Recrystallization from aqueous methanol gave 2-(1-imidazolylmethyl)-3-[4-(N-phenylsulphonylcarbamoyl)benzyloxy]pyridine (0.38 g), m.p. above 250° C. Found: C, 61.47; H, 4.40; N, 12.63. C23H20N4O4S requires: C, 61.59; H, 4.50; N, 12.49%.
