Rational synthesis of pyrazolopyrimidines via cyclocondensation of ynones obtained from the Sonogashira reaction

Abstract

Pyrazolopyrimidines combine the structural and electronic properties of both pyrazole and pyrimidine, imparting unique characteristics that make them valuable in medicinal chemistry and drug discovery. We successfully developed an atom economic protocol for the synthesis of a series of pyrazolo-fused pyrimidines by employing various ynones and 3-aminopyrazole using K₂CO₃ as a base in ethanol. The reactions proceeded under milder conditions, furnishing the desired products in moderate to excellent yields.