Dimethyl Sulfoxide → 2-Bromo-6-(3,3-ethylenedioxypyrrolidine-1-yl)pyridine

Participants

Reaction Steps

Then, to a solution of 2.8 ml of oxalyl chloride in 100 ml of dichloromethane were added dropwise 4.6 ml of dimethyl sulfoxide in a dry ice-acetone bath while stirring, a solution of 5.9 g of the 2-bromo-6-(3-hydroxypyrrolidin-1-yl)pyridine in 50 ml of dichloromethane and finally 17 ml of triethylamine, and the temperature was returned to room temperature over 1 hour. The reaction mixture was washed with water and brine, dried over anhydrous magnesium sulfate and concentrated. To the residue were added 50 ml of toluene, 7 ml of ethylene glycol and a catalytic amount of p-toluenesulfonic acid monohydrate, followed by heating under reflux for 3 hours while removing water. After cooling, it was washed with a saturated aqueous sodium hydrogen carbonate solution and brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography with 5–7% ethyl acetate/hexane, to give 6.3 g of the title compound.

Provenance & Evidence