AROMATIC RADICAL NUCLEOPHILIC-SUBSTITUTION REACTIONS INITIATED BY SODIUM AMALGAM IN LIQUID-AMMONIA

Neither 1-chloronaphthalene nor 2-chloroquinoline reacted with Ph2P- ions in liquid ammonia. However, in the presence of sodium amalgam [Na(Hg)], reaction did occur, and the substitution products 1-naphthyldiphenylphosphine and 2-quinolyldiphenylphosphine (isolated as the P-oxides), respectively, were obtained in good yield. p-Bromoanisole reacted with Na(Hg) amalgam in the presence of Ph2P- ions in liquid ammonia to give anisole as the only product, but when benzonitrile was used as a redox catalyst, a good yield of the substitution product p-anisyldiphenylphosphine (isolated as the P-oxide) was obtained. It is believed that Na(Hg) amalgam initiated these S(RN)1 reactions. Preparative-scale reactions gave good yields of the substitution products.