4-Isoxazolecarboxylic acid, 5-(4-broMophenyl)-3-Methyl-, Methyl ester

1423699-80-2

1228689-61-9

To a stirred solution of methyl 2-(4-bromobenzoyl)-3-(methylamino)but-2-enoate (0.78 g, 2.5 mmol) in acetic acid (10 mL) was added hydroxylamine hydrochloride (0.17 g, 2.5 mmol) under nitrogen atmosphere. After addition, the reaction mixture was heated to reflux for 2 hours under nitrogen protection. Upon completion of the reaction, the mixture was concentrated under reduced pressure to afford the crude product methyl 5-(4-bromophenyl)-3-methylisoxazole-4-carboxylate (0.66 g, 89% yield), which could be used for subsequent reactions without further purification.