Synthesis and physical properties of chlorodi(o-totyl)phosphine, lithium di(o-totyl)2P(CH2)nP(o-totyl) (n 1-4, 6, 8)

The starting material chlorodi(o-tolyl)phosphine has been prepared by the reaction of phosphorus trichloride and the Grignard of o-chlorotoluene. The intermediate lithium di(o-tolyl)phosphide was obtained by the direct reaction of lithium metal and chlorodi(o-tolyl)phosphine in tetrahydrofuran. Lithium di(o-tolyl)phosphide reacted smoothly with ω,ω'-dihaloalkanes, X(CH2)nX (n 1-4, 6, 8, X Cl or Br) to form the tertiary diphosphines (o-tolyl)2P-(CH2)nP(o-tolyl)2. Chlorodi(o-tolyl)phosphine and the diphosphines (o-tolyl)2P-(CH2)nP(o-tolyl)2 (n 1-4, 6, 8) were characterised by elemental analyses and 1H, 31P and 13C NMR spectral analyses