| abstract |
Novel compounds are provided of formula (I) or a pharmaceutically acceptable salt, amide or ester thereof, wherein R1 is selected from hydrogen, methyl, ethyl and prodrug amide group. R2 is selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy, halo-substituted lower alkyl, lower alkylthio, nitro, acetamino and -SO¿2R?7 wherein R7 is lower alkyl. R3 is selected from hydrogen and prodrug ester group. R?4, R5 and R6¿ are independently selected from the group consisting of hydrogen, hydroxy, halogen, lower alkyl, lower alkoxy, halo-substituted lower alkyl, nitro, amino, acetamino, aminomethyl and -SO¿2R?7 wherein R7 is lower alkyl. The compounds of formula (I) are subject to the proviso that: 1) when R?4, R5 and R6¿ are hydrogen, R2 is not methoxy and 2) not more than one of R?4, R5 and R6¿ is nitro or -SO¿2R?7. The compounds of the present invention are useful in the treatment of dopamine-related neurological and psychological disorders, as well as in the treatment of cognitive impairment, attention deficit disorders and addictive behavior disorders. |