Efficient Synthesis of Naphthopyranopyrimidine Derivatives Using Copper(II)/Polyimide Linked Covalent Organic Frameworks: A Solvent-Free and Microwave Assisted Approach

Efficient synthesis of naphthopyranopyrimidine derivatives using copper(II)/polyimide linked covalent organic frameworks (Cu(II)/PL-COF) has been achieved through a solvent-free and microwave-assisted method. This one-pot protocol combines β-naphthol, aromatic aldehydes, and N,N-dimethylbarbituric acid. The process offers various advantages, including safe operation, minimal pollution, fast product formation, and easy setup due to microwave irradiation and a lack of solvents. Additionally, the catalyst demonstrates high reusability, allowing for multiple repetitions of the reaction without experiencing any significant loss in activity.