Eco-friendly One-Pot Synthesis of Oxamide

Abstract A novel, eco-friendly one-pot synthesis of oxamide was developed using nontoxic starting materials, offering a safer alternative to traditional methods. The procedure yields a highly pure oxamide precipitate within 2 days. By optimizing key reaction parameters including temperature, ascorbic acid/ammonia ratio, and ammonia concentration, the precipitation yield can be finely tuned. The resulting oxamide was comprehensively characterized by X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), and one-dimensional/two-dimensional (1D/2D) nuclear magnetic resonance (NMR). Concurrently, the liquid supernatant was analyzed by EDX, NMR, and mass spectrometry (MS), revealing the bioactive metabolite l-threonic acid as the sole major byproduct, with no other toxic compounds detected.