Trifluoromethanesulfonic acid → 5-Bromo-2-chloro-4-hydroxybenzonitrile

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-chloro-4-hydroxybenzonitrile (1, 10 g, 65 mmol) in acetonitrile (200 mL) at −30° C. was added dropwise trifluoromethanesulfonic acid (10 mL, 71 mmol). The solution was stirred for 10 min at −30° C., before adding of N-bromosuccinimide (16.2 g, 91 mmol). After 18 h stirring at ambient temperature, the solution was quenched with aqueous saturated sodium hydrogen carbonate. The organic layer was extracted with ethyl acetate two times, washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The resulting crude residue was purified on a Biotage® purification apparatus (silica gel, 5 to 40% ethyl acetate in hexanes gradient) to yield the title compound (13 g, 56 mmol, 86%) as a white solid.

Provenance & Evidence