Substituted bicyclic derivatives for treating central nervous system disorders

摘要

The present invention relates to compounds of the formula and the pharmaceutically acceptable salts and solvates thereof wherein X1, X2, X3, R1, R2, R3 and R4 are as defined herein. The invention also relates to pharmaceutical compositions containing the above compounds and to methods of treating shizophrenic and shizo-affective disorders, and related disorders which may be treated by administering compounds having dopaminergic activity such as the above compounds of formula 1.