The determination of the initial deprotonation site of 2-chloro- and 2-methoxypyridine duringreaction with BuLi−LiDMAE has been investigated. A series of experiments on deuteratedregioisomers revealed a direct lithiation at C-6 excluding a potential first classical ortholithiationand lithium equilibration in the reaction medium. These results suggested that the formation oflithium aggregates at the neighboring of the pyridinic nitrogen atom favored BuLi delivery at C-6as well as 6-lithio intermediate stabilization.