synthesis of melatoninreceptorligands. In order to complete the structure-activity relationships and to obtain antagonists to the melatoninreceptor, a new series of naphthalenic analogues of melatonin have been synthesized. Modifications include deletion of the 7-methoxy group, replacement of the ethylene moiety, replacement of the amidic function by bioisosteres, and replacement of the naphthalenic nucleus