5-Hydroxy-6-bromo-7-amino- and 5, 7-dihydroxy-6-bromo-s-triazolo [2, 3-a] pyrimidines (III and IV) reacted with piperidine or morpholine to form the corresponding 6-piperidino-(V and VII) or morpholino-(VI and VIII) derivatives. Reaction of (IV) with thiourea gave the 6-amidinothio derivative (IX), which was converted into disulfide compound (X) by the action of alkali. Reaction of (III) with thiourea gave the 5-hydroxy-7-amino derivative (XII) and this reaction in alkaline medium gave the sulfide compound (XIII).