Dimethyl Sulfoxide → 4-([1,1'-Biphenyl]-2-yl)-2-bromo-1H-indene

Participants

Reaction Steps

A cold solution (5° C.) of compound 5 (40 g, 149 mmol, 1 equiv), dimethyl sulfoxide (400 mL) and water (5 mL) was treated in one portion with N-bromosuccinimide (39.8 g, 224 mmol, 1.5 equiv). The bath was removed and the reaction allowed to stir at room temperature overnight. The reaction was poured into water (1 L) and extracted with ethyl acetate (2×500 mL). The combined organic layers were washed with saturated brine (1 L), dried over sodium sulfate, and concentrated under reduced pressure. The resulting residue was dissolved in 500 mL of toluene and p-toluenesulfonic acid (5.6 g, 29.4 mmol, 0.2 equiv) was added. This mixture was refluxed for 20 hours while removing water with a Dean-Stark trap. The reaction was cooled to room temperature and concentrated under reduced pressure. The resulting residue was purified over silica gel (1 Kg), eluting with heptanes to give compound 6 (39 g, 75% yield) as a light yellow solid.

Provenance & Evidence