Hydrogen Bromide → 3-(4-Fluoro-phenyl)-benzo[b]thiophen-6-ol

Participants

Reaction Steps

29.96 g 3-(4-Fluoro-phenyl)-6-methoxy-benzo[b]thiophene in 230 ml acetic acid were treated with 130 ml (62% aq) HBr at 125° C. for 4 h. The solution was added slowly to a cooled solution of 210 g NaOH in 600 ml water, the pH was adjusted to 8-9, and the inorganic phase was extracted with EtOAc. The combined organic phases were washed with brine and dried with Na2SO4. Column chromatography on silica gel with hexane:EtOAc 4.1 yielded 20.0 g (73%) 3-(4-Fluoro-phenyl)-benzo[b]thiophen-6-ol as light brown solid, MS: 244(M).

Provenance & Evidence