(2R)-1-(3-chloro-2-pyrazinyl)-2-methylpiperazine and salts thereof

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): wherein HA is a pharmaceutically acceptable acid and R 1 -R 4 are each independently selected from the group consisting of hydrogen, halogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, and di-C 1 -C 6 -alkylamino-C 2 -C 6 -alkoxy. The invention also relates to the use of said compound to manufacture a medicament for the treatment of a serotonin-related disorder.