Tetrabutylphosphonium chloride

190.9 mL of P(C4H7)3 (154.7 g, 0.764 mol) was added to a flask equipped with a stirrer and a reflux condenser. The flask contained 100 mL of dried and degassed diethyl ether. 96.5 mL of butyl chloride (84.938 g, 0.918 mol) was added, and the solution was stirred under reflux for 2 weeks. This produced a very small amount of crystalline white product. To accelerate the reaction, the diethyl ether was stripped by distillation, and the reaction was continued under reflux for 1.5 days, during which the size of the product layer increased. The mixture was cooled to room temperature, forming a solid product layer, and 50 mL of diethyl ether (for storage) was added on top. The diethyl ether was then decanted, and the product was dissolved in 100 mL of acetone. After adding 1200 mL of diethyl ether, the product precipitated. The precipitate was filtered, washed with 3 × 150 mL of diethyl ether, and dried under vacuum to give a white powder of Tetrabutylphosphonium chloride (161.8 g, 0.680 mol, 89%).