Compounds having dopaminegic activity are provided, having the formula: wherein R1 and R2 are each, independently, hydrogen, C1-10 alkyl, or (CH2)mR4, wherein R4 is phenyl or naphthyl which may be substituted by one or two substituents selected from the group consisting of C1-6 alkyl, halogen, C1-6 alkoxide and trifluoromethyl and m is 1 to 5; and R3 is hydrogen or C1-6 alkyl; or pharmaceutically acceptable salts thereof.