Synthesis of novel spiro‐fused pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidines

Abstract

AbstractNew pyrazolo[4′,3′:5,6]pyrido[2,3‐d]pyrimidines, with an associated spiro‐3,3′‐oxindole attachment, were prepared by three‐component combinations of 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione with a pair of reactants chosen from a pyrazol‐5‐one, a pyrazole‐5‐amine, a barbituric acid, or a 6‐aminouracil.