Preparation of 4-azaindole and 7-azaindole dimers with a bisalkoxyalkyl spacer in order to preferentially target melatonin MT1 receptors over melatonin MT2 receptors

Several 4-azaindole and 7-azaindole dimer analogues of melatonin with a bisalkoxyalkyl spacer between the position 5 of each heterocycle were synthetized. Our aim was to investigate the influence of the spacers length on the selectivity of such compounds for the MT1 receptors over the MT2 receptors. Our results suggest the distance between indole ring seems to be an important parameter in determining the potency of binding with melatonin receptor site.