Pyridine → HCID 67397745, compound

To a suspension of 2-{[4-(carboxymethyl)-1,3-thiazol-2-yl]thio}-2-methylpropionic acid resin (5.0 g) synthesized in Example 461-4 in dimethylformamide (20 mL) were added pyridine (1.2 ml) and 4 mol/L-hydrochloric acid-dioxane solution (2.3 ml) and the mixture was gently stirred at room temperature for 30 min. The resin was collected by filtration, and washed three times with dimethylformamide. To the resin were added dimethylformamide (20 mL), pyridine (0.75 ml) and 2-chloro-1,3-dimethylimidazolinium chloride (1.6 g), and the mixture was stirred at room temperature for 30 min. To the reaction mixture was added heptylamine (1.4 ml), and the mixture was stirred at room temperature overnight. The resin was collected by filtration from the mixture, successively washed three times with dimethylformamide, once with water and methanol, three times with tetrahydrofuran, once with methanol, and finally three times with dichloromethane, and vacuum dried to give the title pale-yellow resin (5.2 g).