Bromine → Methyl 3-bromo-5-(4-chlorophenyl)-4-methylthiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of methyl-5-(4-chlorophenyl)-4-methylthiophene-2-carboxylate (prepared according to the procedure reported in WO 2007092751, 4.0 g, 15.0 mmol) in chloroform (50 ml) at 25° C. was added zinc chloride (2.06 g, 15.0 mmol) followed by the addition of bromine (2.64 g, 0.85 ml, 16.5 mmol) in a dropwise manner under a nitrogen atmosphere. The resulting mixture was stirred at 60-65° C. for 1.5 hr. The progress of the reaction was monitored by TLC. The reaction mixture was cooled to 0° C. and quenched with water (30 ml). The resulting organic layer was washed with 10% aqueous sodium bicarbonate solution (2×50 ml) and dried over anhydrous Na2SO4. The solvent in the organic layer was evaporated under reduced pressure to obtain a crude product, which was then purified by column chromatography over silica gel (100-200 mesh) using 3% ethyl acetate in hexanes as an eluent to obtain the title compound (2.2 g, 42.53%);

Provenance & Evidence