Studies on Organophosphorus Compounds XXVIII. An Improved Synthetic Route to 1-Amino-Substituted Benzyl Phosphonic and -Phosphinic Acids
作者:Chengye Yuan、Youmao Qi
DOI:10.1055/s-1988-27610
日期:——
An improved method for the synthesis of 1-aminosubstituted benzyl phosphonic and -phosphinic acids under mild conditions is described. It consists of the reaction of diphenoxy chlorophosphine (1) or dichlorophenylphosphine (6) with substituted benzaldehydes 2 and a phosphoramidate 3 in the presence of a Lewis acid, followed by selective cleavage of the protective group of the resultant 1-(phosphorylamino)-substituted benzylphosphonate 4 or phosphinate 7, 9. A tentative reaction mechanism is postulated.
New α-aminophosphonates of the type (OCH2CMe2CH2O)P(O)CH(NHCO2R)(R′) [6a–i, 7a–e, and 8a–c] have been synthesized in high yields by a three-component reaction using (OCH2CMe2CH2O)PCl (3), benzamide (or urethane or benzyl carbamate), and an aldehyde without using any catalystundersolvent-freeconditions. This route can be readily adapted for bis-aminophosphonates as well as optically active binaphthoxy