B(Br)(Br)Br.C[O:6][C:7]1[C:15]2[C:11](=[CH:12][O:13][N:14]=2)[CH:10]=[CH:9][CH:8]=1.O.C(=O)([O-])[O-].[Na+].[Na+]>ClCCl>[N:14]1[O:13][CH:12]=[C:11]2[CH:10]=[CH:9][CH:8]=[C:7]([OH:6])[C:15]=1218.5 ml of a 1M solution of boron tribromide in dichloromethane are added to a solution of 1.38 g (9.25 mM) of 7-methoxy-2,1-benzisoxazole in 50 ml of dichloromethane cooled to −78° C., and the mixture is then stirred at ambient temperature overnight. The reaction medium is poured into water and the mixture is brought to pH=7-8 by adding a solution of sodium carbonate, and then extracted with dichloromethane. The organic phase is dried over magnesium sulfate and concentrated under vacuum. The crude product obtained is purified by silica gel chromatography, elution being carried out with a methylcyclohexane/ethyl acetate mixture (gradient of 100/0 to 50/50; v/v). The expected product is obtained in the form of a yellow solid with a yield of 10%.
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