Uses
(2-Methoxyethyl)triphenylphosphonium Bromide is an intermediate for the synthesis of (Z)-Triprolidine Oxalate Salt (T814007), which is an antihistaminic agent with anticholinergic properties. Triprolidine is used to treat and prevent symptoms associated with allergies. Triprolidine is also used in combination with cold medicine to provide relief for flu-like symptoms.
Synthesis
a) Triphenylphosphine (300 g, 1.14 mol) and 2-bromoethyl methyl ether (200 g, 1.43 mol) were refluxed in toluene (1 L) for 24 hours. Upon completion of the reaction, the reaction mixture was cooled to 30 °C and filtered to afford (2-methoxyethyl)triphenylphosphonium bromide (450 g, 78%). Subsequently, the product (450 g) was reacted with pyrrolidine (96 g, 1.37 mol) in methanol (500 mL) at 60°C for 2 hours. At the end of the reaction, methanol was removed by distillation and the resulting solid was suspended in toluene (appropriate amount), cooled to 30°C and filtered to give 2-(1-pyrrolidinyl)ethyltriphenylphosphonium bromide (450 g, 91%).NMR (D2O) δ: 1.67 (m, 4H), 2.46 (m, 4H), 2.78 (m, 2H), 3.41 (m, 2H), 7.68 ( m, 15H).
References
[1] Tetrahedron Letters, 2008, vol. 49, # 5, p. 824 - 826
[2] Patent: WO2007/141803, 2007, A2. Location in patent: Page/Page column 5-6
