A process for producing butyrophenone derivatives of the formula: ##EQU1## which comprises reacting a compound of the formula: ##SPC1## With an amine of the formula H-W (wherein Ar represents a group of either one of the formulas: ##SPC2## Z is a secondary amino group and W is the residue of an amine excluding a hydrogen atom therefrom). The said butyrophenone derivatives and their salts exhibit a variety of beneficial pharmacological activities including a central and autonomic nervous system depressing activity.