formula iii preferably the enantiomers are prepared from a tetraalkylammonium salt form b of the amine of formula iii or from the hydroquinine salt form a of the amine of formula iii the compounds of formula i can be purified by the usual known methods for example by crystallization precipitation chromatography or extraction the compounds of formula i and their enantiomers can be converted to metal salts or to addition salts with nitrogenous bases according to methods known per se these salts can be obtained by reacting a metal base alkali metal or alkaline earth metal for example ammonia an amine or a salt of an organic acid with a compound of formula i or its enantiomers in a solvent as examples of pharmaceutically acceptable salts there can be mentioned the salts with alkali metals sodium potassium lithium or with alkaline earth metals calcium magnesium the ammonium salt or the salts of nitrogenous bases ethanolamine trimethylamine methylamine benzylamine n benzyl u03b2 phenethylamine choline arginine leucine lysine n methylglucamine the compounds of formula i and their enantiomers have advantageous pharmacological properties these compounds have a strong affinity for cholecystokinin cck and gastrin receptors and are thus useful in the treatment and prevention of disorders linked to cck and to gastrin in the nervous system and the gastrointestinal system in this way these compounds can be used for the treatment of the prevention of psychoses of anxious disorders of panic attacks of parkinson 39 s disease of tardive.