Diphenyl Ether → 2,3-Bis(methylsulfanyl)pyridine

Participants

Reaction Conditions

Reaction Steps

A stirred solution of 250 ml of diphenyl oxide was heated to 200° C. A 54 g quantity of the 5-chloro-6-(methylthio)-2-pyridinecarboxylic acid/5,6-bis(methylthio)-2-pyridinecarboxylic acid mixture described above was added portionwise as a solid. The mixture was stirred for 1 hour with the temperature being maintained below 235° C. The mixture was cooled to 100° C., diluted with xylene and cooled to room temperature, then extracted three times with 75 ml of 6N HCl. The combined aqueous fractions were back-washed with diethyl ether, then stirred with CH2Cl2 and made strongly basic with 25% NaOH. The organic layer was separated, washed with water, then brine, and dried (Na2SO4). The solids were removed from the organic layer by filtration, then the filtrate was evaporated leaving a brown oil which was purified on a Kugelrohr distillation apparatus and 23.6 g of an oil obtained. The components of the oil were separated employing high pressure liquid chromatography (Porasil, 3% diethyl ether/hexane) and 19.42 g of 2,3-bis(methylthio)pyridine (b.p. 85° C. at 0.3 mm Hg) and 0.77 g of 3-chloro-2-(methylthio)pyridine (b.p. 80° C. at 0.3 mm Hg) obtained, both as colorless oils.

Provenance & Evidence