A green and novel method for the preparation of α-aminophosphonates using eggshell as catalyst. X-ray study

International audienceAn efficient and eco-friendly green methodology is developed for the synthesis of series of a-aminophosphonate derivatives from diverse aldehydes, anilines and triethyl phosphite by using environmentally benign and cost-effective Eggshells as solid heterogeneous base catalyst. The reaction is conducted by the stepwise one pot condensation through Kabachnick-Fields addition reaction in ethanol at room temperature during 25-30 min. High yield, short reaction time, solvent-free condition, waste to wealth, and optimization with the design of experiment are the major advantages of this method. In addition, this study examines the influence of different solvents, temperature and the amount of catalyst on the yield of the reaction. A single crystal of (2S)diethyl (phenyl) ((4-fluorophenyl)-aminophosphonate (3g) has been obtained after recrystallization from ethanol/dichloromethane (9/1) and selected for X-ray diffraction study. Compound 3g crystallizes in the monoclinic space group P2 1 /c. The structure of the obtained compounds was confirmed by 1 H, 13 C, and 31 P NMR spectroscopy, IR spectroscopy, as well as elemental analysis