Ethyl 1-(6-amino-9-((2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)-9H-purin-2-yl)-1H-pyrazole-4-carboxylate

Ethyl 1-(6-amino-9-((2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)-9H-purin-2-yl)-1H-pyrazole-4-carboxylate is a key intermediate in the synthesis of Regadenoson, where it provides the purine nucleoside core linked with a pyrazole moiety and undergoes subsequent functional group transformations such as ester modification and side-chain optimization to yield the final regadenoson structure, which serves as a selective A2A adenosine receptor agonist.