An Expedient Synthesis of Novel Derivatives of Pyrido[2,3‐d]pyrimidines Using Magnetically Supported ZrO2 Nanocatalyst

An efficient synthesis of pyrido2,3‐d]pyrimidine derivatives via one‐pot multicomponent reactions of 6‐amino‐2‐(alkylthio)pyrimidin‐4(3H)‐one, 3‐cyanoacetylindole and arylaldehydes using Fe₃O₄@ZrO₂] as magnetically recyclable nanocatalyst is reported. This protocol furnished the desired products in good to excellent yields (70–93 %) and lower reaction times. The catalyst could be easily and efficiently separated from the final product solution by an external magnet and be reused in 5 consecutive runs without any significant activity decrease.