H. Krawczyk, A SIMPLE SYNTHESIS OF 2-SUBSTITUTED 2-AMINOETHYLPHENYLPHOSPHINIC ACIDS, Phosphorus, sulfur and silicon and the related elements, 118, 1996, pp. 195-204
Piperidine catalysed reaction of methyl phenylphosphinylacetic acid 1
with paraformaldehyde and primary or secondary alcohols gave methyl ph
enyl(1-alkoxymethyl)vinylphosphinates 3a-f. Conjugate addition of prim
ary amines or ammonia to 3 followed by hydrolysis of the resulting 2-a
minophosphinates 5 and 7 afforded 2-aminoethylphenylphosphinic acids 6
and 8 respectively.