Boron tribromide → Methyl 5-hydroxybenzofuran-2-carboxylate

Participants

Reaction Steps

A solution of 5-methoxy-benzofuran-2-carboxylic acid methyl ester (5.0 g, 24 mmol) in 50 mL DCM at 0° C. was treated portionwise with boron tribromide (4.4 mL of a 1 M solution in DCM). After 3 hours, the reaction mixture was carefully quenched with 50% NH4OH. The organic layer was separated and washed 1×50 mL brine, dried (Na2SO4), and concentrated in vacuo to give 2 g (43%) of the title compound pure enough for subsequent use. 400 MHz 1H NMR (DMSO-d6) δ 9.47 (s, 1H), 7.56 (s, 1H), 7.45 (d, 1H, J=8.8 Hz), 7.00 (s, 1H), 6.91 (d, 1H,J=8.8 Hz), 3.81 (s, 3H).

Provenance & Evidence