Iodine → 2-Iodo-6-(trifluoromethyl)pyridin-3-amine

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Reaction Steps

1.56 g (6.17 mmol) of iodine are added, portionwise, to a mixture, stirred under argon at 20° C., of 1 g (6.17 mmol) of 3-amino-6-(trifluoromethyl)pyridine and 1.25 g (6.17 mmol) of silver sulphate in 40 ml of ethanol. The stirring is maintained for 18 hours. The insoluble material is removed by filtration and is washed with ethanol, the filtrate is concentrated under reduced pressure, and the residue is taken up in 100 ml of dichloromethane. The organic phase is washed successively with 20 ml of a 5% aqueous solution of sodium hydroxide, 40 ml of water and 20 ml of a saturated aqueous solution of sodium chloride, dried over sodium sulphate, concentrated under reduced pressure and then purified by silica column chromatography (eluents:heptane-ethyl acetate). 1.17 g of the expected product are thus isolated, which product is used as it is in the subsequent synthesis.

Provenance & Evidence