Bisphosphonic compounds. Part 3. Preparation and identification of tetraalkyl methylene- and (α-halomethylene)bisphosphonates by mass spectrometry, NMR spectroscopy and X-ray crystallography

The preparation and identification of tetraalkyl methylenebisphosphonates {XYC[P(O)(OR)2]2; X = Y = H, Cl or Br and R = alkyl} have been studied. Detailed procedures are given for the synthesis of XYC[P(O)(OR)2]2(X = Y = H; R = hexyl; X = Y = Cl or Br and R = Me). 1H, 13C and 31P NMR data are reported including 1JCH, 2JCP, 3JCP and 2JPP coupling constants. The fragmentation of 19 XYC[P(O)(OR)2]2 has been studied in the gas phase. The solid state structures are given for two compounds (X = Y = Cl, R = Pri and X = Y = Br, R = Me).