Boron tribromide → 4-Bromo-5-fluorobenzene-1,2-diol

Participants

Reaction Conditions

Reaction Steps

To a cooled (−78° C.) solution of 4-fluoroveratrole (5.0 g, 32 mmol) in dichloromethane (106 mL) was slowly added a solution of tribromoborane in dichloromethane (1M, 96 mL, 96 mmol, 3.0 eq.). The reaction mixture was warmed to 20° C. and stirred overnight. The reaction mixture was poured into ice water, extracted with ethyl acetate (3 times). The combined organic layer was washed with an aqueous solution of sodium bicarbonate, dried over sodium sulfate and filtered. The volatiles were removed in vacuo. The brown solid was diluted with chloroform (50 mL) and dichloromethane (10 mL). A solution of bromine in carbon tetrachloride (5 ml) was slowly added. After 3 hours, the volatiles were removed in vacuo. Purification by flash chromatography afforded the title compound (6.51 g, 98%) as a brown solid

Provenance & Evidence