The present invention relates to a process for the preparation of compounds which are therapeutically active in the central nervous system.In one aspect, the invention relates to a process for the preparation of compounds of the general formula (I): ##STR00001## wherein HA is a pharmaceutically acceptable acid and R.sub.1 R.sub.4 are each independently selected from the group consisting of hydrogen, halogen, C.sub.1 C.sub.6-alkyl, C.sub.1 C.sub.6-alkoxy, and di-C.sub.1 C.sub.6-alkylamino-C.sub.2 C.sub.6-alkoxy.The invention also relates to the use of said compound to manufacture a medicament for the treatment of a serotonin-related disorder.