4-Bromophenol → 2-Bromo-3-(4-bromophenoxy)-6-methoxybenzo[b]thiophene 1,1-dioxide

Participants

Reaction Conditions

Reaction Steps

To a solution of 2,3-dibromo-6-methoxybenzo[b]thiophene 1,1-dioxide (12.5 g, 35.3 mmol) in THF (175 mL) at room temperature was added 4-bromophenol (6.49 g, 37.1 mmol) and Cs2CO3 (34.5 g, 106 mmol). The resulting suspension was warmed to 50° C. and the reaction turned faintly yellowish green after a few minutes and then subsequently faintly pink, the mixture remained a suspension. After 4 h at 50° C. the mixture was cooled to room temperature, diluted with water (175 mL), and stirred for 15 min. The solution was transferred to a separator funnel and the phases were separated. The aqueous layer was extracted with EtOAc (3×100 mL) and the combined organic layers were then washed with brine (100 mL), dried over anhydrous Na2SO4, filtered and concentrated in vacuo to afford 2-bromo-3-(4-bromophenoxy)-6-methoxybenzo[b]thiophene 1,1-dioxide (14.7 g, 33.0 mmol, 93% yield) as a faintly pink solid which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm==3.83 (s, 3H), 6.92-7.03 (m, 3H), 7.25-7.35 (m, 2H), 7.39-7.50 (m, 2H).

Provenance & Evidence