Triphenylphosphine (5.03g, 18.8 mmol) was suspended in dry acetonitrile (20 ml) and cooled to 0°C in a 250 ml round-bottomed shlenck, using an Argon-vacuum regime. Bromine (0.96 ml, 18.8 mmol) was added dropwise to the reaction mixture, allowing the solution to become colourless after each portion was added, and was then allowed to warm to ambient temperature. Diethylene glycol (0.9 ml, 9.4 mmol) was added and the reaction heated at reflux (80°C) under dinitrogen for 18 h then allowed to cool to ambient temperature. The solvent was removed under reduced pressure (using using a pretrap). The resulting orange solid was stirred in diethyl ether (50 ml) for 1 h to give an orange solution and precipitate, which was filtered. The solvent was removed from the orange-coloured filtrate under reduced pressure to give an orange oil. This was further purified via Kügelrhor distillation to give a clear oil (bp 100°C under high vacuum). Yield: 1.45 g, 6.3 mmol, 67%.

¹H NMR (400 MHz, 298 K, CDCl₃): δ_H 3.83 (t, ³J_HH = 5.97 Hz, 2H, OCH₂), 3.48 (t, ³J_HH = 5.76 Hz, 2H, OCH₂CH₂).

¹³C {¹H} NMR (101 MHz, 298 K, CDCl₃): δ_C 70.96 (CH₂, OCH₂), 30.18 (CH₂, OCH₂CH₂).

ESI-MS: m/z 72.4 [M-2Br]⁺.

IR v cm^-1: 2966 w, 2856 w, 1739 m, 1438 w, 1421 m, 1361 w, 1279 m, 1226 w, 1111 s, 1030 m, 1005 m, 948 m, 726 m, 691 m, 663 m.

CHN (calculated for C₄H₈OBr₂): C 20.78 % (20.72 %), H 3.49 % (3.48 %).