Methyl 5-iodothiophene-2-carboxylate

5380-42-7

2712-78-9

88105-22-0

Steps for the synthesis of methyl 5-iodothiophene-2-carboxylate (P-1): methyl thiophene-2-carboxylate (5.0 g, 28.7 mmol) was dissolved in 35 mL of anhydrous carbon tetrachloride under nitrogen protection. Iodine (3.65 g, 14.37 mmol) and [bis(trifluoroacetoxy)iodo]benzene (6.67 g, 15.52 mmol) were then added sequentially. The reaction mixture was stirred overnight at room temperature. Upon completion of the reaction, it was diluted with the addition of dichloromethane and extracted with 10% sodium thiosulfate solution to remove unreacted iodine. The organic layer was separated, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast column chromatography (eluent: 40% hexane/60% chloroform) to give a white solid. For further purification, the resulting solid was co-milled with pentane to remove residual feedstock, resulting in the target compound P-1 (4.8 g, 63% yield). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ 3.89 (s, 3H), 7.28 (d, J = 3.9 Hz, 1H), 7.45 (d, J = 3.9 Hz, 1H).