Central nervous system active butyrophenone derivatives in which gamma -piperazinobutyrophenone derivatives of the formula, WHEREIN R1 is hydrogen, amino, C1-C5 alkanoylamino, C1-C4 alkylamino or N-(C1-C4 alkyl)(C1-C5 alkanoyl) amino; R2 is hydrogen or halogen; R3 is hydrogen, halogen, C1-C4 alkyl, C1-C4 alkoxy or trifluoromethyl; and m is 0, 1 or 2, and acid addition salts thereof, can be prepared by reacting an indole derivative of the formula, WHEREIN R2, R3 and m are the same as defined above, and R4 and R5 are hydrogen or C1-C4 alkyl respectively, with an oxidizing agent to yield an o-alkanoylamino- gamma -piperazinobutyrophenone derivative of the formula, WHEREIN R2, R3, R4, R5 and m are the same as defined above, and further, if necessary, hydrolyzing the product to yield an o-amino- gamma -piperazinobutyrophenone derivative of the formula, WHEREIN R2, R3, R5 and m are the same as defined above, and further diazotizing, if desired, in case R5 is hydrogen, the obtained o-amino- gamma -piperazinobutyrophenone derivative and subsequently decomposing the resultant diazonium compound to replace the diazonium group by hydrogen. Among the butyrophenone derivatives thus obtained, those in which R1 is amino, alkanoylamino, alkylamino or N-alkylalkanoylamino and those in which R1 is hydrogen and R2 is halogen substituted at meta-position to carbonyl group are novel compounds.
Piperazinobutyrophenone derivatives