Methyl 2,4-dioxo-4-(3-bromophenyl)butyrate (10.3 g, 36.1 mmol) was used as a raw material and suspended in anhydrous methanol (100 mL). To this suspension was added hydroxylamine hydrochloride (3.8 g, 54.2 mmol). The reaction mixture was heated to reflux for 90 minutes. Upon completion of the reaction, the mixture was cooled to room temperature and an ice/water mixture (200 mL) was added. After continued stirring for 20 minutes, the mixture was filtered through a Brinell funnel and washed with cold water. The resulting light yellow solid was dried in a vacuum oven to give methyl 5-(3-bromophenyl)isoxazole-3-carboxylate (8.9 g, 87% yield).
