Wiktionary
pyrazolopyrimidine
n. (context chemistry English) Any of a class of sedative and anxiolytic drugs with similar effects to benzodiazepines, their molecules typified by the linked six-sided pyrimidine ring and five-sided pyrazole ring.
Wikipedia
Pyrazolopyrimidine
Pyrazolopyrimidines are a series of isomeric heterocyclic chemical compounds with the molecular formula CHN. They form the central core of a variety of more complex chemical compounds including some pharmaceuticals and pesticides.