Therapeutic agents

A pharmaceutical composition useful for treating depression in humans which comprises an anti-depressantly effective amount of a compound of the formula I:

• ##STR44## or a pharmaceutically acceptable salt thereof, in which R.sub.1 is selected from the group consisting of cycloalkyl groups containing 3 to 7 carbon atoms, cycloalkylalkyl groups in which the cycloalkyl group contains 3 to 6 carbon atoms and the alkyl group contains 1 to 3 carbon atoms, alkenyl groups containing 2 to 6 carbon atoms, alkynyl groups containing 2 to 6 carbon atoms and groups of formula II:
• ##STR45## in which R.sub.9 and R.sub.10, which are the same or different, are selected from the group consisting of H, halo and alkoxy groups containing 1 to 3 carbon atoms;
• R.sub.2 is selected from the group consisting of H and alkyl groups containing 1 to 3 carbon atoms;
• R.sub.3 and R.sub.4, which are the same or different, are selected from the group consisting of H, straight or branched chain alkyl groups containing 1 to 4 carbon atoms, alkenyl groups having 3 to 6 carbon atoms, alkynyl groups having 3 to 6 carbon atoms and cycloalkyl groups in which the ring contains 3 to 7 carbon atoms;
• R.sub.5 and R.sub.6, which are the same or different, are selected from the group consisting of H, halo, trifluoromethyl, alkyl groups containing 1 to 3 carbon atoms, alkoxy groups containing 1 to 3 carbon atoms, alkylthio groups containing 1 to 3 carbon atoms and phenyl, or R.sub.5 and R.sub.6, together with the carbon atoms to which they are attached, form a second benzene ring optionally substituted by at least one halo, alkyl or alkoxy group containing 1 to 4 carbon atoms or the substituents of the second benzene ring together with the two carbon atoms to which they are attached form a further benzene ring, in combination with a pharmaceutically acceptable carrier.

A method for treating depression in humans which comprises administering to a human in need thereof an anti-depressantly effective amount of a compound of the formula I:

• ##STR54## or a pharmaceutically acceptable salt thereof, in which R.sub.1 is selected from the group consisting of cycloalkyl groups containing 3 to 7 carbon atoms, cycloalkylalkyl groups in which the cycloalkyl group contains 3 to 6 carbon atoms and the alkyl group contains 1 to 3 carbon atoms, alkenyl groups containing 2 to 6 carbon atoms, alkynyl groups containing 2 to 6 carbon atoms and groups of formula II:
• ##STR55## in which R.sub.9 and R.sub.10, which are the same or different, are selected from the group consisting of H, halo and alkoxy groups containing 1 to 3 carbon atoms;
• R.sub.2 is selected from the group consisting of H and alkyl groups containing 1 to 3 carbon atoms;
• R.sub.3 and R.sub.4, which are the same or different, are selected from the group consisting of H, straight or branched chain alkyl groups containing 1 to 4 carbon atoms, alkenyl groups having 3 to 6 carbon atoms, alkynyl groups having 3 to 6 carbon atoms and cycloalkyl groups in which the ring contains 3 to 7 carbon atoms;
• R.sub.5 and R.sub.6, which are the same or different, are selected from the group consisting of H, halo, trifluoromethyl, alkyl groups containing 1 to 3 carbon atoms, alkoxy groups containing 1 to 3 carbon atoms, alkylthio groups containing 1 to 3 carbon atoms and phenyl, or R.sub.5 and R.sub.6, together with the carbon atoms to which they are attached, form a second benzene ring optionally substituted by at least one halo, alkyl or alkoxy group containing 1 to 4 carbon atoms or the substituents of the second benzene ring together with the two carbon atoms to which they are attached form a further benzene ring, in combination with a pharmaceutically acceptable carrier.