Synthesis of a staurosporine analogue possessing a 7-azaindole unit instead of an indole moiety

The synthesis of a new staurosporine analogue possessing a 7-azaindole unit instead of an indole moiety is described. This synthesis could be achieved by coupling a sugar moiety previously tosylated in 2′ position to the azaindolocarbazole aglycone. Nucleophilic substitution on the carbon bearing the tosyl group yielded to the key cyclization leading to a compound in which the carbohydrate part is linked to both indole and azaindole nitrogens.