The purpose of the present invention is to provide a novel low-molecular-weight compound which exhibits orexin receptor agonist activity and is expected to be useful as a prophylactic agent or therapeutic agent for narcolepsy and the like. The present invention provides: a compound represented by general formula (I) (wherein the symbols are as defined in the description) and having orexin receptor agonist activity, or a pharmaceutically acceptable acid addition salt of the compound； and an orexin receptor agonist which contains the compound or a pharmaceutically acceptable acid addition salt of the compound.
