[Synthesis of imidazo[1,2-a]pyridine derivatives and their reactions]

By the reaction of 2-benzoylmethylimidazoles (1a, b) with polarized olefins (2, 3) in the presence of K2CO3, the corresponding imidazo[1,2-a]pyridine derivatives (4, 5) were obtained. Methylsulfinylimidazopyridine derivative (7) obtained by the reaction of 5b with m-chloroperbenzoic acid (m-CPBA), easily underwent nucleophilic substitution to give the corresponding substituted compounds (8a--e). The substitution of chloroimidazopyridine derivative (11) with nucleophiles produced the corresponding substituted compounds (12a--d).