KINETICS AND A MECHANISTIC STUDY OF α-AMINO PHOSPHONATES ALONG WITH A GREEN PROTOCOL FOR SYNTHESIS AND CHARACTERIZATION

A developed method for the synthesis of α-amino phosphonates from a condensation reaction of trialkyl phosphite, aldehydes and amine has been reported in the presence of succinic acid as a catalyst under solvent-free conditions. Excellent yields, short reaction time, mild reaction conditions, higher availability, lower costs, more environmentally friendly, lack of need for column chromatography and simple work-up procedure were the advantages of this new protocol. The reaction was monitored spectrally and followed the second order kinetics. Moreover, the effect of solvent, concentration, and different alkyl groups within the trialkyl phosphite (structural effect) on the rate of the reactions was investigated. The first step of the mechanism was determined as a rate determining step (RDS) and the rate constant (Lnk1, Lnk1/T) depended on reciprocal temperature was in good consistent with Arrhenius and Eyring equations. The activation energy (Ea) and parameters (ΔG‡, ΔS‡ and ΔH‡) of the reaction were calculated from the obtained experimental data.