Bis(trimethylsiloxy)phosphine as key synthon for synthesis of new aminomethylphosphinic acids with N-alkyl 4-hydroxypiperidines moieties

Abstract

The convenient synthesis of new aminomethylphosphinic acids and their derivatives containing N-alkyl 4-hydroxypiperidines moieties was developed. The addition of bis(trimethylsiloxy)phosphine to N-alkyl 4-piperidones proceeds under mild conditions to give PH-phosphinates as key compounds for preparation of trimethylsilyl esters of above acids via interaction with various aminals. The further treatment of phosphinic acids trimethylsilyl esters with the methanol resulted in the water-soluble corresponding acids. The structures of aminomethylphosphinic acids and their precusors 1–3 with substituted piperidine moieties were confirmed by the 1H, 13C, 31P NMR spectra.