Gum arabic-OPOH as a new natural-based green catalyst for the one-pot pseudo-four-component synthesis of naphtho[1,2-][1,3]oxazines.

Gum arabic-OPOH (GA-OPOH) as a unique natural-based green catalyst was synthesized by the reaction of phosphorus pentoxide with gum arabic. The structure and properties of the catalyst were studied several analysis methods such as FT-IR, MAPPING, EDS, SEM, XRD, and TGA. The efficiency of the above-mentioned catalyst was investigated for the synthesis of naphtho-1,3-oxazines a pseudo-four-component reaction of primary amines, formaldehyde, and 2-naphthol under the solvent-free grinding condition at room temperature using an electrical mortar-heater. The obtained results indicated that GA-OPOH is a highly efficient green catalyst for the synthesis of naphtho[1,2-][1,3]oxazines with high yields, simple workup, and benign reaction condition.