N-Alkylation of Some Imidazopyridines

6-Bromo-2-(4-(4-fluorophenoxy)phenyl)-4H-imidazo[4,5-b]pyridine (I) and 2-[4-(4-fluorophenoxy)phenyl]-5H-imidazo[4,5-c]pyridine (III) were prepared by the reaction of 5-bromo-2,3-diaminopyridine and 3,4-diaminopyridine with sodyum metabisulfite adduct of 4-(4-fluorophenoxy)benzaldehyde (1), respectively. Alkylation of these compounds with 1-(chloromethyl)-4-methoxybenzene under basic conditions (K2CO3) in DMF) were formed as mainly N4 regioisomer (II) and N5 regioisomer (IV). Their regioisomeric structures were assigned with 2D-NOESY (Nuclear Overhauser Effect Spectroscopy) spectra.