Synthesis
The general procedure for the synthesis of (3-bromopropyl)triphenylphosphonium bromide from triphenylphosphine and 1,3-dibromopropane was as follows: Triphenylphosphine (511 g, 1.85 mol, purity 95.0%) and toluene (800 g) were added to a reactor equipped with a stirrer, and stirred until completely dissolved. Under the condition of temperature lower than 5℃, 1,3-dibromopropane (371g, 1.82mol, purity 99.0%) was added slowly dropwise, and the dropwise addition time was controlled within 1 hour. After the dropwise addition, the reaction mixture was heated to reflux and the reflux reaction was maintained for 17 hours. After completion of the reaction, the mixture was cooled to room temperature to obtain the suspension. The suspension was filtered at 20 °C and the solid product was collected. The solid product was washed with toluene (2 x 800 g) and then dried under vacuum at 60 °C for 21 h. White crystalline 3-bromopropyltriphenylphosphonium bromide (Olo-IM3) was obtained in a yield of 757 g (1.63 mol) in 89.6% yield.
References
[1] Chemical Communications, 2014, vol. 50, # 45, p. 5993 - 5996
[2] Tetrahedron Letters, 2003, vol. 44, # 24, p. 4547 - 4550
[3] Patent: US2007/232814, 2007, A1. Location in patent: Page/Page column 24
[4] Tetrahedron Letters, 1985, vol. 26, # 47, p. 5747 - 5748
[5] Tetrahedron, 1981, vol. 37, # 16, p. 2855 - 2860
