The present invention relates to a novel serotonin reuptake inhibitor which also exhibits 5-HT2C antagonistic action (antidepressive and anxiolytic effects), in particular, 5-HT2C inverse agonistic action comprising Compound (1): or a pharmaceutically acceptable salt thereof wherein R1, R2, R3 and R4 are independently hydrogen or C1-6 alkyl etc.; R5 is C4-7 alkyl or —(CR8R9)r-E; R6, R7, R8 and R9 are independently hydrogen, fluorine or C1-6 alkyl; A is C6-10 aryl or heteroaryl etc.; r is 1, 2, 3 or 4; E is C3-8 cycloalkyl or C6-10 aryl etc.; L is oxygen, sulfur or —NR10—; n is 1, 2 or 3; R10 is hydrogen or C1-6 alkyl etc.; and X is hydrogen or halogen etc.