We report herein a four-step preparation of the title compound. Gentisic acid (1) was firstly onverted into its diacetate (2) by treatment with acetic anhydride in the presence of concentrated sulfuric acid. Treatment of the diacetate with oxalyl chloride in dichloromethane in the presence of dimethylformamide followed by N-O-dimethyl-hydroxyamine hydrochloride and pyridine gave 2, 5