2-Bromo-3-chlorothiophene synthesis

Yield: 100%

Reaction Conditions:

with N-Bromosuccinimide;acetic acid in chloroform for 1.5 h;Reflux;

Steps:

1
Compound 28-1 (0457) To a solution of 3-chlorothiophene (6.52 g, 55 mmol) in CHCl₃ (30 mL) and AcOH (30 mL) was added NBS (9.80 g, 55 mmol). The mixture was heated at relux for 1.5 h, then cooled to room temperature. Water (70 mL) was added and the mixture was extracted with CHCl₃ (30 mL×2). The combined organic layers were washed with sat. NaHCO₃ (40 mL) and brine (30 mL), dried over anhydrous Na₂SO₄, filtered, concentrated to afford 28-1 as a brown oil (10.02 g, quantitive yield) which used for the next step directly.

References:

Nivalis Therapeutics, Inc.;Wasley, Jan;Rosenthal, Gary J.;Sun, Xicheng;Strong, Sarah;Qiu, Jian US9138427, 2015, B2 Location in patent:Page/Page column 304