AMINOPHOSPHONIC ACIDS BEARING HETEROCYCLIC MOIETY. PART 4.1 SYNTHESIS OF 2-PYRIDYL AND 4-PYRIDYLMETHYL-(AMINO)PHOSPHONIC ACIDS

Abstract

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