A compound represented by the formula (I), an optically active isomer thereof, or a pharmaceutical acceptable salt thereof:wherein R2 represents a hydrogen or the like； R3 represents methyl group or the like； R20 represents a halogen atom or the like； q represents an integer of 0 to 3； Z represent nitrogen atom, CH, or the like； R4 represents hydrogen or the like； R5 represents hydrogen or the like； R6 represents a substituted alkyloxy and the like； p represents an integer of 0 to 3； X represents bond, CH2, oxygen atom, NH, or the like； any one or more of R5 and R6, R5 and R4, R6 and R4, X and R5, X and R4, X and R6, and R3 and R6 may combine to each other to form a ring, which is used for preventive and/or therapeutic treatment of a disease caused by tau protein kinase 1 hyperactivity such as a neurodegenerative diseases (e.g. Alzheimer disease).
