A solution of 6.0 g (0.045 mol) of 1,3-oxathiolane-2-thione (90% pure) and 8.0 g (0.045 mol) of N-bromosuccinimide in 70 ml of methylene chloride was stirred at 0° for 3 hr and then at ambient temperature overnight. The solution was filtered and concentrated to give 13.2 g of solid. Two recrystallizations from a mixture of carbon tetrachloride, methylene chloride, and pentane gave 4.4 g (34%) of colorless solid, mp 111—113°. Further recrystallization gave a sample which melted at 117.5—118.5°; NMR τ 6.52 (s, 4) and 7.03 (s, 4); IR (KBr) 1650 and 1730 cm-1.
Anal. Calcd for C7H8BrNO3S2: C, 28.19; H, 2.70; Br, 26.80; N, 4.70; S, 21.50. Found: C, 28.16; H, 3.31; Br, 27.36; N, 5.07; S, 21.77.
Treatment of a solution of 1,3-oxathiolane-2-thione in carbon tetrachloride with NBS gave the same product.
© Collected Ruslan Anatolievich Kiper, burewestnik@mail.ru