PROVIDED IS A COMPOUND REPRESENTED BY THE FORMULA (I): WHEREIN EACH SYMBOL IS AS DEFINED IN THE SPECIFICATION, OR A SALT THEREOF, WHICH HAS AN AMPA (Α-AMINO-3-HYDROXY-5-METHYL-4-ISOXAZOLEPROPIONIC ACID) RECEPTOR POTENTIATING ACTION. THE COMPOUND OF THE PRESENT INVENTION IS USERFUL AS A PROPHYLACTIC OR THERAPEUTIC DRUG FOR DEPRESSION, SCHIZOPHRENIA, ALZHEIMER’S DISEASE OR ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) AND THE LIKE.