Thionyl Chloride → 2-Chloronicotinoyl chloride

Participants

Reaction Steps

A mixture of 50.0 g (0.317 mole) of 2-chloropyridine-3-carboxylic acid and 120 ml of thionyl chloride was heated at reflux for 3 hours. The resulting solution was concentrated to dryness. The resulting oil was diluted twice with methylene chloride and concentrated to dryness to give 55.4 g of 2-chloropyridine-3-carbonyl chloride. Total yield 99%. This acid chloride was added to a mixture of 76.9 g (0.315 mole) of 2-methylthio-2-imidazoline hydrochloride, 1 liter of methylene chloride, and 63.7 g (0.630 mole) of triethylamine. This mixture was heated at reflux for 16 hours. The resulting solvent was removed by evaporation and the residue was stirred with water for 15 minutes. A white solid was collected by filtration and dried to give 69.2 g of 1-(2-chloropyridine-3-carbonyl)-2-methylthio-2-imidazoline; melting point 100°-102° C. Total yield 86%. This compound exhibits the following formula ##STR8##

Provenance & Evidence