Ethanol → 2-Amino-5-fluoro-3-iodopyridine

Participants

Reaction Steps

5 g (44.6 mmol) of 2-amino-5-fluoropyridine, 13.9 g (44.6 mmol) of silver sulfate and 400 mL of ethanol are put in a 500-mL two-necked flask equipped with a magnetic stirrer. Then 11.31 g (44.6 mmol) of iodine powder is added, in small portions. It is stirred at room temperature for 24 hours. The insoluble matter is removed by filtration and is washed with ethanol, and the filtrate is concentrated at reduced pressure. The residue thus obtained is taken up in a mixture of ethyl acetate (200 mL) and sodium carbonate solution (200 mL). After separation, the organic phase is washed successively with a 25% aqueous solution of sodium thiosulfate then with a saturated aqueous solution of sodium chloride, then it is dried over sodium sulfate and concentrated at reduced pressure. The resultant solid is purified by chromatography on a silica column, eluting with a mixture of n-heptane and ethyl acetate. We obtain 2.67 g (11.22 mmol) of the expected product.

Provenance & Evidence