Iodine → Methyl 5-iodothiophene-2-carboxylate

To a solution of thiophene-2-carboxylic acid methyl ester (5.0 g, 28.7 mmol) in 35 mL of anhydrous carbon tetrachloride was added iodine (3.65 g, 14.37 mmol) and [Bis(trifluoroacetoxy)iodo] benzene (6.67 g, 15.52 mmol). This mixture was stirred overnight at room temperature. Dichloromethane was then added and the mixture was extracted with a solution of sodium thiosulfate 10%. The organic layer was evaporated and the residue was purified flash chromatography (hexane 40%:chloroform 60%) to give a solid which was triturated with pentane in order to remove remaining starting material affording compound P-1 as a white solid (4.8 g, 63% yield).