Phosphorus pentachloride → Pyridine-3-sulfonyl chloride

Participants

Reaction Steps

A mixture of pyridine-3-sulphonic acid (3.0 g) and PCl5 (7.9 g) was stirred in an oil bath maintained at 150° for 3 hours, in a flask fitted with a reflux condenser. After cooling, the liquid formed set solid. The solid was triturated with xylene (10 cm3) and evaporated at the water pump in an oil-bath maintained at a maximum temperature of 110°, and with a splash-head to reduce frothing. The evaporation was repeated twice more, and the residue was pumped on a rotary evaporator to remove the last traces of xylene. The yellow, semi-crystalline mass (6.87 g) occluded unreacted PCl5.

Provenance & Evidence