Facile one-pot mono-dealkylation of H-phosphonate esters in high yield

The readily available dialkyl H-phosphonates (RO)2P(O)H, where R = Me, Et, iPr, nBu and Bn can be mono-dealkylated by heating at reflux in excess tert-butylamine. Where R = Me or Bn then crystals of [(CH3)3CNH3]+ [ROP(O)HO]− form in the reaction vessel on overnight standing.