Thermal Reactions of Malic Acid Benzylamine Salts

Abstract

Malic acid, a component present in fruit, is known to be an important precursor for the prebiotic formation of polyaspartic acid. Malic acid is a dicarboxylic acid, possessing one hydroxyl group. It yields many types of crystalline salts with amino compounds. Although the thermal reactions of the amino salts have been reported, their dehydration reaction pathway has not been studied. This paper describes the dehydration process using thermal gravimetry and differential thermal analysis. The results show that the malic acid monobenzylamine and the dibenzylamine salts release water molecules during an endothermic reaction to afford malic acid benzylimide and malic acid dibenzylamide, respectively. The latter compound is stable up to 230 ºC.