| abstract |
Novel compounds of formula (I): n n n wherein X 1 , X 2 , X 3 and X 4 , n, R 1 , R 2 and R 3 are defined in the specification, and pharmaceutically acceptable salts and prodrugs of the compounds of formula (I) have therapeutic uses. These compounds are useful for the treatment of disorders of the central nervous system; damage to the central nervous system; cardiovascular disorders; gastrointestinal disorders; diabetes insipidus, and sleep apnea. They are particularly useful for the treatment of obesity. |