Amino acids as catalysts for the enolisation study of m-Methylacetophenone

Abstract

Amino acids have been used as catalysts for the study of kinetic of enolisation of m-Methylacetophenone, in which iodination has been the chosen method. Several parameters like effect of ketone concentration, effect of dielectric constant, effect of catalysts etc. have been investigated for their effect on enolisation kinetics. The study is focused on β-alanine, dl-alanine, l-alanine and Glycine for their effects on the rate. The order of the rate constants obtained has been found to be in the order of increasing dipole moments of the amino acids i.e. l-alanine < Glycine < dl-alanine < β-alanine. With an increase in the temperature from 323 K to 338 K, an increase in the rate was from 1.3 to 2.12 mol−1 min−1. The ongoing reaction was found to be bimolecular in nature. The values of different thermodynamic parameters like Entropy (ΔS≠), Enthalpy (ΔH≠), Energy of activation (ΔEa) and Gibbs free energy (ΔF≠) were found to be 6.20 e.u., 24.74 cal mol−1, 25.20 k cal mol−1 and 24.54 cal mol−1 respectively. Keywords: Amino acids, Catalysis, Enolisation, Kinetics, m-Methylacetophenone, Ketones