FUSED IMIDAZOLE DERIVATIVES AND MEDICINAL COMPOSITION THEREOF

Fused imidazole derivatives represented by general formula (I) or salts thereof, wherein X represents oxygen, sulfur, methylene (-CH2-) or -NR-; Y represents methylene (-CH2) or -NR-; R and R are the same or different and each represents hydrogen or lower alkyl; and m and n are the same or different and each represents an integer of from 0 to 4, provided that m plus n is an integer of from 2 to 4. The compounds have the activity of inhibiting steroid 17-20 lyase and are efficacious in the treatment and prevention of prostatic cancer, prostatic hypertrophy, mammary cancer, mastopathy, uterus myoma, endometriosis, etc.