A regioselective synthesis of 4, 7-dimethoxy 5-and 6-azaindoles 2 has been achieved, based on the appropriate choice of ortho-directing or ortho-repulsing groups in the formylation of a pyridine ring. Studies on the regioselectivity of the formylation step and on the preparation of azidoacrylate intermediates 4 are described in this paper. The reactivity of the 5-and 6-azaindole structures towards BBr3-mediated selective monodemethylation ...
