Studies on Organophosphorus Compounds; XLVI. A Facile and Direct Route to Dialkyl 1-(Benzyloxycarbonylamino)alkylphosphonates and Dialkyl or Diphenyl α-(Benzyloxycarbonylamino)benzylphosphonates
17 September 2002 (online)
A simple and direct method for the preparation of dialkyl 1-(benzyloxycarbonylamino) alkylphosphonates and dialkyl or diphenyl α-(benzyloxycarbonylamino)benzylphosphonates in high yields consists of the three-component reaction of benzyl carbamate, an alkanal or a benzaldehyde, and a dialkyl (or dipbenyl)-phosphite in acetyl chloride at 0°C (for alkanals) or in acetic acid containing thionyl chloride at 20-70°C (for benzaldehydes). Removal of the benzyloxycarbonyl group by standard methods or selective hydrolysis of the dialkyl phosphonate moiety leads to the formation of derivatives of aminoalkylphosphonic acids bearing free amino or acidic functions, which are useful intermediates in phosphonopeptide synthesis.