One-pot Synthesis of Novel α-Aminophosphonate Derivatives Containing a Pyrazole Moiety

Synthesis of novel N-protected α-aminophosphonates 6 were achieved with high yields through copper (II) triflate catalyzed one-pot three component reaction process. It involves the reaction of aryl substituted pyrazolaldehydes, methylcarbamate and trimethylphosphite or triphenylphosphite using copper (II) triflate as lewis acid catalyst in dry dichloromethane at room temperature. A mechanism for this condensation reaction is proposed. Cleavage of the N-methyloxycarbonly group under acid hydrolysis afforded the free α-aminophosphonates 8 in quantitative yields. The structures of all new compounds were established by elemental analysis IR, ¹HNMR and mass spectral data. ( Ibrahim El Sayed, Salah M. El Kosy, Mohamed F. Abdel Magied, Mohamed A. Hamed, Ahmed Abdel Aleem El Gokha and Mostafa.M.Abd El-Sattar. One-pot Synthesis of Novel α-Aminophosphonate Derivatives Containing a Pyrazole Moiety. Journal of American Science 2011;7(9):604-608). (ISSN: 1545-1003). http://www.americanscience.org.