Benzenesulfonyl chloride → 2-Benzenesulfonylamino-3-iodo-5-methylthiopyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-amino-3-iodo-5-methylthiopyridine (7.63 g) in pyridine (30 ml), benzenesulfonyl chloride (7.9 ml) was added at 15 to 30° C. under nitrogen atmosphere and the mixture was stirred at 60° C. for 15 hours. The reaction solution was then poured into a saturated aqueous sodium hydrogencarbonate solution, extracted with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. A solution of the resulting crude bis(benzenesulfonyl) product in a mixture of methanol/dioxane (1:1, 200 ml) was added a 1N aqueous potassium hydroxide solution (64 ml) at 15 to 30° C. and the mixture was stirred at 60° C. for 1 hour. The reaction solution was then poured into a saturated aqueous sodium hydrogencarbonate solution, extracted with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The resulting residue was separated using silica gel column chromatography (methanol chloroform=1:50) to obtain 6.4 g (56%) of the desired product as a white powder.

Provenance & Evidence