Synthesis and preliminary pharmacological assessment of novel 9-alkylamino substituted pyrimidino-[2,1-f]-purines.

Two series of N9-alkylaminomethyl-, alkylpiperazino-, alkylpiperidino-substituted 1,3-dimethyl-(hexahydropyrimidino)- and (tetrahydropyrimidono)-[2,1-f]-purines were prepared and their physicochemical and pharmacological properties were described. The most active in central nervous system tests were the compounds with phenylpiperazinealkyl substituent i.e. 1,3-dimethyl-2,4-dioxo-9-[N1N4-(phenyl)-piperazinopropyl]-1, 3,6,7,8,9- hexahydropyrimidino-[2,1-f] purine 6a and its butyl and isobutyl homologs 9 and 12. The compounds depressed statistically significantly spontaneous locomotor and amphetamine activity and showed sedative, analgetic and hypothermizing properties.