Yield:97511-06-3 100%

Reaction Conditions:

with tetra-N-butylammonium tribromide in methanol;dichloromethane at 20; for 15 h;Product distribution / selectivity;

Steps:

26.A

Step A: A solution of tetrabutylammonium tribromide (15.0 g, 312 mmol) in dichloromethane (80 ml) was added dropwise to a solution of 2-acetylbenzothiophene (5.0 g, 28 mmol) in dichloromethane (20 ml) and methanol (20 ml) at room temperature. At completion of the addition, the resulting red-orange solution was stirred at room temperature for 15 hours. The mixture was concentrated under vacuum and the residue was taken into ethyl acetate and water. The layers were separated and the aqueous phase was extracted with ethyl acetate. The combined organic extracts were washed with saturated aqueous sodium bicarbonate and brine and dried over anhydrous sodium sulfate to give the desired bromo compound (7.3 g, 100%): ¹HNMR (300 MHz, CDCl₃) δ 8.07 (s, 1H), 7.91 (dd, J=12.0, 8.1 Hz, 2 H), 7.42-7.53 (m, 2H), 4.47 (s, 2H).

References:

US2006/52378,2006,A1 Location in patent:Page/Page column 100