AMINOPHOSPHONIC ACIDS BEARING HETEROCYCLIC MOIETY - PART 4 - SYNTHESIS OF 2-PYRIDYL AND 4-PYRIDYLMETHYL-(AMINO)PHOSPHONIC ACIDS

2-Pyridyl and 4-pyridylmethyl(amino)phosphonic acids are not available by hydrolysis of corresponding phosphonic esters by means of aq. hydr ochoric acid. During hydrolysis of these esters a cleavage of C-P bond occurrs, which leads to a repulsion of phosphorus moiety and formatio n of the corresponding amine. It was found, that silylation of pyridyl methyl(amino)phosphonic diethyl esters with bromotrimethylsilane and s ubsequent solvolysis of the silylated product with methanol led to the expected 2-pyridyl and 4-pyridylmethyl(amino)phosphonic acids in high yield.