A thermochemical study on the reactions of aniline with formaldehyde in the presence of acid medium

Abstract

Using thermochemical parameters, the reaction course and the products of the reactions between aniline and formaldehyde using molar ratios of 4 : 1, 2 : 1 and 1 : 1 in the presence of acid medium have been analysed. Data on ΔH^O_f and ΔH^O_r were obtained experimentally by adopting combustion and solution calorimetry: theoretical data were obtained by Benson's thermochemical approach. The calculated values for the different possible structures have been compared with the experimental values of the reaction products. Thus, 4,4'-diaminodiphenylmethane has been deduced as the product for the 4 : 1 and 2 : 1 aniline: formaldehyde reactions and poly-anhydro-p-aminobenzylalcohol for the 1 : 1 reaction. The structure of the products were further confirmed by spectral methods. Inferences from thermochemical data were found to agree with spectral information as well as that reported by other authors.