Iodine → Methyl 4-iodo-5-methylthiophene-2-carboxylate

Participants

Reaction Steps

To a solution of methyl 5-methylthiophene-2-carboxylate (287 mg, 1.837 mmol) in MeOH (7 mL), was added silver sulfate (687 mg, 2.205 mmol) and I2 (513 mg, 2.021 mmol). The mixture was stirred at room temperature under N2 overnight. The reaction was quenched with sat. Na2SO3. The aqueous layer was extracted with EtOAc (3×). The combined organic layers were washed with brine (1×), dried (Na2SO4) and concentrated in vacuo. This was purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/min, 100% hexanes for 144 mL, gradient to 10% EtOAc in hexanes over 1140 mL) to afford in order of elution methyl 4-iodo-5-methylthiophene-2-carboxylate. LCMS calc.=207.1. found=206.9 (M+Na)+. 1H NMR (500 MHz, CDCl3): δ 767 (s, 1H); 3.87 (s, 3H); 2.46 (s, 3H).

Provenance & Evidence