Alkylation of 8-chloro-1,3-dimethylxanthine (I) with benzyl bromide and K2CO3 affords the 7-benzyl purine (II). This is then condensed with N-Boc-piperazine (III) in EtOH upon heating at 120 C in a sealed vessel to provide the 8-piperazinyl derivative (IV). Finally, deprotection of (IV) employing trifluoroacetic acid leads to the title compound