Dibromomethane → 2-Furfurylimino-1,3-dithietane

A mixture of 13.7 g. of triethylammonium furfuryldithiocarbamate, 10.5 ml. of methylene bromide, and 7.0 ml. of triethylamine in 100 ml. of dimethylformamide was stirred for several hours and then poured into ice-water. The oily product was partitioned into ether and the ether mixture was extracted with 3N hydrochloric acid. After extracting the acidic solution with methylene chloride, it was made basic with potassium hydroxide solution and re-extracted with methylene chloride. The methylene chloride mixture, after water washing, drying, and concentrating in vacuo afforded 4.9 g. of the desired dithietane as a yellow oil.