Butyl bromide → 2-Butyl-1,3-dithiane

30 ml. of a 1.6M solution of n-butyllithium in n-hexane were added dropwise to a solution of 4.8 g. of 1,3-dithiane in 150 ml. of tetrahydrofuran under an atmosphere of nitrogen at -20° to -25° C. After 2 hours stirring, 6 g. of n-butyl bromide in 60 ml. of tetrahydrofuran were added dropwise to the reaction mixture, which was stirred for 1 hour at -20° to -25° C. and for a further 30 minutes at room temperture and then concentrated under reduced pressure. The residue was dissolved in diethyl ether, washed with water and an aqueous solution of sodium chloride, dried over magnesium sulphate and concentrated under reduced pressure to give 6.8 g. of the title compound having the following physical characteristics: