2,6-Dimethylphenol → 5-(4-hydroxy-3,5-dimethylphenyl)-5H-dibenzo[b,d]thiophenium bromide

Participants

Reaction Steps

Eaton's Reagent (100 mL) was added dropwise to a solution of dibenzothiophene oxide (15.0 g, 74.9 mmol) and 2,6-dimethylphenol (9.15 g, 74.9 mmol) in dichloromethane (200 mL) at 0° C. The reaction was warmed to r.t. and stirred for 4 h, then cooled to 0° C. and quenched with the slow addition of water (200 mL) keeping the reaction temperature below 20° C. The aqueous phase was extracted with ethyl acetate (3×100 mL) and potassium bromide (17.9 g, 0.150 mmol) in water (50 mL) was added to the aqueous layer under vigorous stirring. The slurry was stirred at r.t. for 1 h, filtered and washed with water (3×200 mL), MTBE (3×200 mL) and the residue dried in vacuo to afford the title compound (10.1 g, 35%) as an off-white solid. 1H NMR (300 MHz, (CD3)2CO) δ: 9.77 (brs, 10H), 8.52 (d, J=8.1 Hz, 2H), 8.27 (8.1 Hz, 2H), 7.95 (t, J=7.8 Hz, 2H), 7.74 (t, J=7.8 Hz, 2H), 7.20 (s, 2H), 2.12 (s, 6H).

Provenance & Evidence