Benzo[d]isoxazol-3-ol

89-73-6

21725-69-9

The general procedure for the synthesis of benzo[D]isoxazol-3-ol from salicylhydroxamic acid is as follows: intermediate 1 (1.92 M in THF solution) was placed in a reaction vial and stirred at 60 °C. CDI (3.84 M, THF solution) was added slowly over 30 minutes. The reaction mixture was heated to reflux and reflux was continued at 60 °C for 2 hours. Upon completion of the reaction, the mixture was cooled to 40 °C and subsequently evaporated to remove the solvent. The residue was quenched with water and the pH was adjusted to 2 with 12 N HCl. The mixture was stirred for 30 min followed by filtration at 10-15 °C to collect the precipitate. The precipitate was washed with ice water and finally dried under reduced pressure at 90 °C to give 3-hydroxybenzisoxazole (Intermediate 2) in quantitative yield.