4546-04-7 NSC203064 Phosphonic acid, (p-phenylenedimethylene)di-, tetraethyl ester Phosphonic acid, [1,4-phenylenebis(methylene)]bis-, tetraethyl ester Tetraethyl p-xylylenediphosphonate p-Bis(diethylphosphono)xylene p-Xylylenebis(diethyl phosphonate)