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 sulphate and 400 ml of ethanol are introduced into a 500 ml two-necked flask equipped with a magnetic stirrer. 11.31 g (44.6 mmol) of powdered iodine are subsequently added in small portions. The stirring is continued at ambient temperature for 24 hours. The insoluble material is removed by filtration and washed with ethanol and the filtrate is concentrated under reduced pressure. The residue thus obtained is taken up in a mixture of ethyl acetate (200 ml) and of a solution of sodium carbonate (200 ml). After separation, the organic phase is washed successively with a 25% aqueous solution of sodium thiosulphate and then with a saturated aqueous solution of sodium chloride, and then dried over sodium sulphate and concentrated under reduced pressure. The resulting solid is purified by silica column chromatography, elution being carried out with a mixture of n-heptane and ethyl acetate. 2.67 g (11.22 mmol) of the expected product are obtained.

Provenance & Evidence