New naphthofuranic analogues of melatonin were designed and synthesized.

Prepared compounds showed good binding affinities at both MT₁ and MT₂ receptors.

Ligand 6a represents the most interesting compound of this series and behaves as an MT₁ partial agonist and MT₂ full agonist.

Lateral chain displacement from position 1–2 has no effect on binding affinity at MT₁ and MT₂.