Sodium amide residues, destroying

PjPjP jP -Tetraphenylmethylenediphosphine 216 Triphenylphosphine (131 g) is added within 10 min to a well-stirred solution of sodium (23 g molar ratio 1 2) in liquid ammonia (1.51) at —75° under nitrogen. Reaction occurs at once, the color changing to deep orange. Ammonium bromide (49 g) is then added to destroy the phenylsodium and sodium amide (exothermal reaction — care ). After 1 h, methylene dichloride (21.5 g), dissolved in ether (20 ml), is added, whereupon the orange color fades. The solution is allowed to come to room temperature, and, when the ammonia has evaporated, the solid residue is washed with water (1.21) and then with methanol (four times with 50 ml) and crystallized from propanol (yield 74 g, 77%) one more crystallization gives the pure compound, m.p. 120.5-121.5°. 

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