New Quinoxaline Derivatives as Potential MT1 and MT2 Receptor Ligands

Ever since the idea arose that melatoninmight promote sleep and resynchronize circadian rhythms, many research groups have centered their efforts on obtaining new melatonin receptorligands whose pharmacophoresinclude an aliphatic chain of variable length united to an N-alkylamide and a methoxy group (or a bioisostere), linked to a central ring. Substitution of the indole ring found in melatoninwith a naphthaleneor quinolinering leads to compounds of similar affinity. The next step in this structural approximation is to introduce a quinoxalinering (a bioisostereof the quinolineand naphthalenerings) as the central nucleus of future melatoninergic ligands.