1,4-DISUBSTITUTED PIPERAZINE DERIVATIVES, PHARMACEUTICAL COMPOSITIONS CONTAINING THEM AND PROCESS FOR PREPARING SAME

1,4-DISUBSTITUED PIPERAZINE DERIVATIVES, PHARMACEUTICAL COMPOSITIONS CONTAINING THEM AND PROCESS FOR PREPARING SAME The invention relates to novel 1,4-disubstituted piperazine derivatives of the general formula (I), pharmaceutically acceptable acid addition and quaternary ammonium salts thereof, pharmaceutical compositions containing them and a process for their preparation. In the general formula (I) (I) R1, R2, R3 and R4 are the same or different and stand for hydrogen or halogen or a trihalomethyl, lower alkyl, lower alkoxy, nitro, hydroxyl, aralkyloxy or an 1-(2-propenyl-4-piperazinyl) group; R5 stands for hydrogen or a C1-4 alkyl group; R6 represents a C3-6 alkyl, alkenyl, alkynyl group or a C-R7 group, wherein R7 means a C2-5 alkyl, alkenyl or alkynyl group; and n is 2 or 3, with the provisos that: R6 is different from isopropyl, n-butyl and isobutyl group when R2, R3, R4 and R5 stand for hydrogen, R1 means 2-chloro and n is 2; R6 is different from isopropyl group when R2, R3, R4 and R5 stand for hydrogen, R1 means 2-chloro and n is 2; or when R2, R3, R4 and R5 stand for hydrogen, R1 means 2-methyl group and n is 2; and R6 is different from propionyl group when R1, R2, R3, R4 and R5 are hydrogen and n means 2, The compounds of the general formula (I) are therapeutically useful for the treatment of diseases arising from a hypofunction of the dopaminergic system.