Methyltriphenylphosphonium Bromide

[1779-49-3] C19H18BrP (MW 357.24) InChI = InChI = 1S/C19H18BrP/c1-21(20,17-11-5-2-6-12-17,18-13-7-3-8-14-18)19-15-9-4-10-16-19/h2-16H,1H3 InChIKey = BKRKYEFQSANYGA-UHFFFAOYSA-N (forms methylenetriphenylphosphorane upon treatment with butyllithium,2 sodamide,3 dimsylsodium,4 or potassium t-butoxide;5 also used as a phase-transfer catalyst6) Physical Data: mp 234–235 °C. Solubility: sol alcohols, DMSO; insol Et2O, THF, benzene, toluene, hexane. Form Supplied in: white solid; widely available. Drying: when used to prepare methylenetriphenylphosphorane, methyltriphenylphosphonium bromide must be strictly dried immediately prior to use for best results. Drying can be achieved effectively by heating the flask containing the phosphonium salt at 110 °C/0.2 mmHg for several hours, or by repetitive (three times or more) azeotropic removal of water with benzene or toluene.