The present invention relates to a pharmaceutical composition comprising as active ingredient a compound of the Formula I <IMAGE> (I) wherein R1 stands for straight or branched chain alkyl comprising 1 to 8 carbon atoms; phenyl alkyl having 7 to 10 carbon atoms; phenyl; or cycloalkyl comprising 3 to 8 carbon atoms; R2 stands for straight or branched chain alkyl comprising 1 to 8 carbon atoms; alkyl comprising 1 to 8 carbon atoms substituted by halogen, hydroxy, alkoxy having 1 to 4 carbon atoms or by one or two phenyl groups; phenyl; or cycloalkyl having 3 to 8 carbon atoms, with the proviso that groups R1 and R2 together contain at least three carbon atoms. The invention also relates to a process for the preparation of compounds of the Formula I by methods known per se. The compounds of the Formula I are phychostimulants having a new spectrum of effect which can be used in therapy for increasing psychical activity (learning and retention) and for treating clinical patterns of depression and deficiencies of learning and retention like in Alzheimer's disease, and are void of side effects (e.g. due to catecholamine release) of known stimulants.
Psychostimulant agent