The objective of the present invention is to provide a novel low molecular weight compound which exhibits an orexin agonist activity and is expected to be useful as an excellent therapeutic or preventive agent for narcolepsy. The present invention provides a compound having an excellent orexin agonist activity represented by general formula (I) [In the formula, each symbol is as defined in the specification.] or a pharmaceutically acceptable acid addition salt thereof, and an orexin agonist which comprises the compound or the pharmaceutically acceptable acid addition salt thereof.
