Full factorial optimization of α-aminophosphonates synthesis using diphenylphosphinic acid as efficient organocatalyst

Diphenylphosphinic acid was used as an efficient and simple catalyst for the synthesis of the alpha-aminophosphonates by multicomponent Kabachnik-Fields reaction in one pot of aromatic aldehyde, aniline and diethylphosphite. Three physicochemical factors including catalyst amount, reaction time and medium temperature were optimized using a full factorial experiment design (FFD). Additionally, a quadratic polynomial regression model was applied for the analysis of the experimental data at a confidence level of 95% with p-values< 0.05. The high signification effect of the reaction time and the medium temperature on the alpha-aminophosphonates synthesis were confirmed by the statistical analysis. Besides, the diphenylphosphinic acid amount showed an effect on the reaction yield. ANOVA exhibited that the coefficient determination of this model up to 99.25%. This eco-friendly procedure was extended for the preparation of series of the alpha-aminophosphonates in ethanol as green solvent, giving the desired products with high chemical yields up to 90%.