DISPLACEMENT ON HALOGEN VS CARBON AND ON HALOGEN VS HYDROGEN OF CERTAIN POLYHALIDES BY DIPHENYLMETHIDE ION IN LIQUID AMMONIA

Sodium and potassium diphenylmethide (I ′), prepared from diphenylmethane (I) and the corresponding alkali amide in liquid ammonia, underwent displacement on halogen with ethylene bromide and iodide to form the dimer, 1,1,2,2-tetraphenylethane (III), and presumably ethylene; in contrast, I′ underwent displacement on carbon (Sn2) with ethylene chloride to give the twofold alkylation product. Similarly, potassio salt I ′ underwent displacement on halogen with 2,3-dibromo-2,3-dimethylbutane, 1,1,2,2-tetrabromoethane, and hexachloroethane to form dimer III and an olefinic product. The olefinic products from the tetrabromo- and hexachloroethanes were dibromoethylene and tetrachloroethylene, respectively; potassio salt I′ also underwent displacement on halogen with these olefinic halides to afford apparently acetylene. Potassio salt I ′ underwent displacement on hydrogen with 1,1-dichloroethane to regenerate I, and displacement on halogen with 1,1,1-trichloroethane and benzotrichloride to form a mixture of I and III; in these cases the halide was converted to an aldimine. Potassio salt I′ underwent displacement on halogen with N-bromosuccinimide to give dimer III and succinimide. © 1968, American Chemical Society. All rights reserved.