Ultrasound-Assisted Preparation of Cu-Doped TiO₂ Nanoparticles as a Nanocatalyst for Sonochemical Synthesis of Pyridopyrimidines

In this study, ultrasonic synthesize of Cu-doped TiO₂ nanoparticles were developed as heterogeneous nanocatalysts targeting the ultrasonic synthesis of substituted-pyridopyrimidines, starting with 3-(aminomethyl)pyridin-2-amine and different arylmethanethiols. This strategy includes, first, the sono-synthesis and characterization of Cu-doped TiO₂ nanoparticles. Then, the catalytic efficiency of the as-prepared nanocatalysts toward the substituted-pyridopyrimidines was evaluated using a sonochemical approach. Overall, this ultrasonic-assisted Cu-doped TiO₂ catalyzed synthesis was found to produce pyridopyrimidine heterocycles with excellent yields (up to 94%).