Synthesis and Spectroscopy of Phosphonate Derivatives of Uracil and Thymine. X-Ray Crystal Structure of Diethyl 6-Uracilmethylphosphonate

A new class of phosphonate ligands, derived from uracil and thymine was designed, prepared and characterised. Dimethyl (4, 7) and diethyl (5, 8) uracilmethylphosphonates have been prepared by the reaction of chloromethyluracil isomers 2 and 3 with trimethyl phosphite and triethyl phosphite, respectively. The corresponding free acids, 5-uracilmethylphosphonic acid 6 and 6-uracilmethylphosphonic acid 9, have also been isolated. The structure of the compounds has been assigned by nmr spectroscopy and, in the case of 8, confirmed by X-ray analysis.