For the evaluation of biological activities, 4-pyrazinoylmorpholine (II) and many new compounds have been synthesized from the N-oxide of II. The reactions of 2-(4-morpholinocarbonyl) pyrazine 4-oxide (IV) with halogenation reagents were examined, and the main product was proved to be 6-chloro-2-(4-morpholinocarbonyl) pyrazine (VII) by correlating the product to the known 2-amino-6-chloropyrazine (XIV).
