Three‐component Strategy for Synthesis of Dihydropyrido[2,3‐ d ]pyrimidine and Spirooxindole Derivatives

A series of heterocyclic compound derivatives, including 2,8‐diamino‐5‐aryl‐5,10‐dihydropyrido[2,3‐ d :6,5‐ d ′]dipyrimidine‐4,6(3 H ,7 H )‐diones and 2,2′‐diamino‐3 H ‐spiro [pyrimido[4,5‐ b ]quinoline‐5,5′‐pyrrolo[2,3‐ d ]pyrimidine]‐4,4′,6′(3′ H ,7′ H ,10 H )‐triones, were synthesized via one‐pot method using Y (OTf) 3 as catalyst. The reaction was performed in aqueous media using readily available and inexpensive 2,6‐diaminopyrimidin‐4(3 H )‐one and aromatic aldehyde as substrates. The present methodology shows attractive characters, such as using water as green reaction media, high catalytic efficiency of catalyst, concise one‐pot method, easy work‐up/purification, and excellent yields.