Ethyl Acetate → 3-(4-Bromophenoxy)-6-methoxybenzo[b]thiophene

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(4-bromophenoxy)-6-methoxybenzo[b]thiophene 1,1-dioxide (230 g, 626 mmol) in THF (3450 mL) was added DIBAL-H (1.0 M in DCM, 3132 mL, 3132 mmol). The mixture was heated to 60° C. for 18 hours. The mixture was cooled down to 40° C. DIBAL-H (1.0 M in DCM or Toluene, 500 mL, 500 mmol) was added. The mixture was refluxed for 6 hours. DIBAL-H (1.0 M in DCM, 300 mL, 300 mmol) was added. The mixture was refluxed for 8 hours, after which time the reaction was cooled to 0° C. over 2 hours. EtOAc (1226 mL) was added very slowly. Rochelle salt solution (884 g, 626 mmol in 6000 mL water) was slowly added (over 3 hours). The resulting solution was aged at room temperature for 18 hours. The organic layer was separated from the aqueous layer. The aqueous layer was extracted with EtOAc (1000 mL). The combined organic layer was washed with brined, dried with anhydrous Na2SO4 and concentrated in vacuo to afford 3-(4-bromophenoxy)-6-methoxybenzo[b]thiophene (149.8 g, 446.9 mmol, 71% yield) as a white solid which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm=3.81 (s, 3 H), 6.46 (s, 1 H), 6.90 (d, J=9.09 Hz, 3 H), 7.16-7.22 (m, 1 H), 7.31-7.40 (m, 2H), 7.46 (d, J=9.09 Hz, 1 H), LC/MS (m/l, MH+): 336.8.

Provenance & Evidence