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

Abstract

An efficient and eco-friendly green methodology is developed for the synthesis of series of α-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 P2₁/c. The structure of the obtained compounds was confirmed by ¹H, ¹³C, and ³¹P NMR spectroscopy, IR spectroscopy, as well as elemental analysis.

Graphical abstract

Keywords:

• α-Aminophosphonates
• eggshell catalyst
• X-ray study
• three-component reaction

Acknowledgements

This work was supported financially by The General Directorate for Scientific Research and Technological Development (DG-RSDT), Algerian Ministry of Scientific Research, Applied Organic Chemistry Laboratory (FNR 2000).

Disclosure statement

There are no conflicts to declare.