Sodium Azide → Methyl 7-fluoro-6-(2-fluorophenylamino)-3-methylbenzo[c]isoxazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 5-acetyl-3,4-difluoro-2-(2-fluorophenylamino)benzoate (example 3, step D) (1.50 g, 4.64 mmol) in a mixture of acetone (36 ml) and H2O (12 ml) was added NaN3 (452 mg, 6.96 mmol). The reaction was heated at 65° C. for 16 h and cooled to room temperature. Acetone was concentrated and the resulting mixture was extracted with EtOAc (2×50 ml). The combined organic solution was washed with brine (50 ml), dried over MgSO4 and concentrated to give a yellow solid. To the solid was added H2O (24 ml) and the reaction was heated at reflux for 3 h. The reaction was cooled to room temperature, filtered, and washed with H2O. The resulting solid was dried under high vacuum with P2O5 at 65° C. for 24 h to give 1.31 g (89%) of methyl 7-fluoro-6-(2-fluorophenylamino)-3-methylbenzo[c]isoxazole-5-carboxylate as a yellow solid.

Provenance & Evidence