Ethoxycarbonylmethyltriphenylphosphonium bromide was prepared as follows: ethyl acetate (5.0 L) was added to triphenylphosphonium, and ethyl bromoacetate (665 g, 4.01 mol) was added dropwise to the mixture with stirring, and after the dropwise addition the reaction mixture was stirred at room temperature for 24 hours. The mixture was then diafiltered and the filter cake was washed three times with ethyl acetate, using 500 mL each time. Vacuum drying of the filter cake gave ethoxymethyltriphenylphosphonium bromide [Ph 3 PCH 2 CO 2 Et]+Br- (1500 g) as a white solid in 92% yield.