Herein, gold nanoparticle-decorated amorphous carbon (Au/AC) was prepared by reducing chloroauric acid and layering it on amorphous carbon. The characteristics of Au/AC were examined using FT-IR, XRD, TGA, SEM, EDS, and XPS. To assess its catalytic activity, Au/AC was tested in a reaction involving anthranilamide and benzyl alcohol at 110 °C for 24 hours. This reaction yielded various 2-phenylquinazolin-4(3H)-one derivatives in moderate to good yields (44-80%). Furthermore, control experiments were conducted to demonstrate the oxidation and cyclization functions of Au/AC. Noteworthy aspects of this approach included the ease of isolating Au/AC (via recrystallization) and the ability to recycle it.