The present invention provides compounds represented by the general formula (I): or pharmaceutical acceptable salts thereof, wherein R 1 is cyano or the like； R 2 and R 3 are hydrogen or the like； R 4 is C 1-6 alkyl or the like； R 5 is C 1-6 alkyl, halo-C 1-6 alkyl, cycloalkyl, cycloalkyl-C 1-6 alkyl, aralkyl or the like； R 6 and R 7 are each hydrogen, C 1-6 alkyl, halo-C 1-6 alkyl, cycloalkyl, C 1-6 alkoxy-C 1-6 alkyl, R 12 R 13 N-C 1-6 alkyl or the like, which exhibit potent dopamine D 2 receptor stimulating activities. The present invention also provides pharmaceutical compositions containing said compound, and uses thereof.
