METALATED METHYLENEDIPHOSPHONATE ESTERS . PREPARATION CHARACTERIZATION AND SYNTHETIC APPLICATIONS

The metalation of esters of tetraalkyl methylenediphosphonates with sodium, potassium, sodium hydride and n-butyllithium to form the corresponding salts, M+[CH(PO3R2)2], is described. These compounds were characterized by 31P and 1H NMR; their synthetic usefulness was demonstrated by the preparation of a variety of alkylates, R′CH(PO3R2)2, and by the preparation of mono and dihalo derivatives, XCH(PO3R2)2 and X2C(PO3R2)2, by direct halogenation. A superior method of halogenation of teraalkyl methylenediphosphonates is also described. The reaction of metalated tetraalkyl methylenediphosphonate with molecular oxygen in toluene solution is shown to be complex. © 1968.