Substituted 3‐Amido and 3‐Amidoalkylbenzopyran Derivatives: Synthesis and Pharmacological Activity as Melatonin Ligands

A novel series of melatonin analogues based on the benzopyran nucleus is described. These compounds are prepared in several steps from substituted 2-hydroxybenzaldehydes. Some of these derivatives competitively inhibit 2-[125I]iodomelatonin binding to chicken brain and ovine pars tuberalis membranes although with reduced affinity compared with melatonin.