Example 2: 330 g (7.17 mol) of anhydrous ethanol was cooled to -15°C under nitrogen protection. Subsequently, 18 g (1.06 mol) of ammonia was passed at this temperature. Next, 200 g (0.907 mol) of diphenylphosphonium chloride was slowly added dropwise over a period of 1 hour. After the dropwise addition was completed, the reaction mixture was gradually warmed to room temperature with stirring and stirring was continued for 3.5 hours. After completion of the reaction, the mixture was cooled, diafiltrated and the solids were washed with ethanol. The filtrate was treated to ensure that it was free of ethanol and residual ammonia. A small amount of precipitate was removed by filtration through glass material. Finally, purification by thin film distillation at a bath temperature of 140 °C and pressure of 0.3 mbar gave 172 g of ethoxydiphenylphosphine in 83% yield of the theoretical value.
