(2R)-1-(3-Chloro-2-Pyrazinyl)-2-Methylpiperazine And Salts Thereof

A process for the preparation of the general formula (I):

• comprising the steps of:
• (i) O-alkylating a 3-pyridinol derivative of the general formula (II) or the corresponding hydrochloride:
• to give another 3-pyridinol derivative of the general formula (III):
• (ii) reacting the 3-pyridinol derivative of the general formula (III) with (2R)-1-(3-chloro-2-pyrazinyl)-2-methylpyrazine of the formula (IV) in the presence of the alkali metal tert-butoxide or an alkali metal tert-butoxide.
• to give a compound of the general formula (V):
• (iii) converting the compound of the general formula (V) to the compound of the general formula (I) by treatment with a pharmaceutically acceptable acid of the formula HA,
• wherein each of R1, R2, R3, and R4, independently, is hydrogen, C1-C6-alkyl, C1-C6-alkoxy, and di-C1-C6-alkylamino-C2-C6alkoxy.