Triethylamine → 2-(4-Chlorobutylthio)pyridine

To a solution of 25.0 g (225 mmol) of 2-mercaptopyridine and 34.5 ml (247 mmol) of triethylamine in 300 ml of ethanol, 28.5 ml (247 mmol) of 1-bromo-4-chlorobutane was added with stirring under ice-cooling, and the mixture was stirred at room temperature for 16 hours. The solvent was distilled off and the residue was dissolved in chloroform. The solution was washed with saturated aqueous sodium bicarbonate and water, and dried. The solvent was distilled off and the residue was purified by column chromatography (eluent: ethyl acetate/hexane =1:3) to give 29.73 g of the desired compound (65.5% yield, pale yellow oil).