C3e Dimer acids were esterified with various short-chain alcohols, namely 2-propanol, n-butanol, n-hexanol, noctanol, 2-octanol and 2-ethyl-l-hexanol by using sulfuric acid as catalyst and benzene as an azeotropic solvent. Various reaction parameters were standardized. In case of isopropyl esters, acid-to-alcohol mole ratio of 1:5 and sulfuric acid concentration of 2% based on the weight of dimer acids were found to be optimum. In case of straightchain primary alcohols, namely n-butanol, n-hexanol and n-octanol, 1:2.5 mole ratio of acid to alcohol and 1% by weight of sulfuric acid were found satisfactory. Esterification reaction rates were determined from the fall in acid value of the product. The reaction followed pseudo first order kinetics. The reaction rates increased with the increase in chainlength of straight-chain primary alcohols from n-butanol to n-octanol. The rate of reaction decreased from n-octanol to 2-ethyl-l-hexanol to 2-octanol due to the branching of the chain in 2-ethyl-l-hexanol and secondary nature of the --OH group in 2-octanol.

SynopsisKinetic studies were carried out on the reaction between ethylenediamine and dimeric fatty acids in melt phase. The reaction was performed at 124, 130, 145, 160, 174, and 190°C and followed by determining the acid value of the product. The polyamidation reaction was found to be of overall second order with an activation energy of 18.2 kcal/g mol up to 90% conversion and of overall third order with an activation energy of 16.4 kcal/g mol above 90% conversion.

SynopsisKinetic studies were carried out on the reaction between ethylenediamine and C,, cycloaliphatic dicarboxylic acid, prepared from dehydrated castor oil fatty acids and acrylic acid, in melt phase. The reaction was performed at six different temperatures ranging from 210 to 260°C and followed by determining the acid value of the product. The polyamidation reaction was found to follow an overall third order kinetics with an activation energy of 15.5 kcal/g mol.

The practical synthetic preparation of glutaric acid has remained a major challenge to date. In the present study, glutaric acid was synthesised by way of one-pot diazoniation/hydrogenation of the readily available L-glutamic acid under aqueous conditions on a gram-scale with good yields. This is the first example of the deamination of the aliphatic primary amine via diazoniation and could afford a practical approach to the production of glutaric acid.