Disclosed are compounds of the formula ##STR1## wherein R.sub.1 represents optionally substituted aryl, heteroaryl, arylalkyl, or cycloalkyl groups; X, Z, and Y are optionally substituted nitrogen or carbon atoms; R.sub.3 and R.sub.4 are organic or inorganic substituents which may together form ring structures; m is zero, one or two; and R.sub.5 and R.sub.6 are are organic or inorganic substituents; and the pharmaceutically acceptable addition salts thereof, which compounds are highly selective partial agonists or antagonists at brain dopamine receptor subtypes or prodrugs thereof and are useful in the diagnosis and treatment of affective disorders such as schizophrenia and depression as well as certain movement disorders such as Parkinsonism.