Pyrazolo[3,4-d]pyrimidine ribonucleosides as anticoccidials. 2. Synthesis and activity of some nucleosides of 4-(alkylamino)-1H-pyrazolo[3,4-d]pyrimidines

Abstract

A series of 4-(alkylamino)-1-.beta.-D-ribofuranosyl-1H-pyrazolo[3,4-d]pyrimidines was synthesized by enzymatic and chemical methods. On the basis of the previous finding that 4-(alkylthio)-1-.beta.-D-ribofuranosyl-1H-pyrazolo[3,4-d]pyrimidines were effective anticoccidial agents, this series was examined for efficacy against Eimera tenella in chicks. The most active anticoccidial agent in the present study was the 4-cyclopentylamino derivative, which cleared chicks of the parasite at 200 ppm in the diet. The 4-diethylamino derivative, which was not toxic in vitro, appeared to be toxic in chicks.