The kinetics of the decarboxylation of n-butylmalonic acid in alkanols and amines

✍ Scribed by Louis Watts Clark

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 457 KB
• Volume: 7
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550070603

✦ Synopsis

Abstract

Rate constants and activation parameters are reported for the decarboxylation of n‐butylmalonic acid in four normal alkanols (hexanol1, octanol1, decanol1, and dodecanol1) and in five amines (aniline, N‐methylaniline, N‐ethylaniline, N‐n‐propylaniline, and N‐n‐butylaniline). Both Δ__H__‡ and Δ__S__‡ of the reaction in both homologous series decrease regularly with increasing length of the hydrocarbon chain of solvent. If we compare data for the reaction in alkanol–amine pairs containing the same total number of carbon atoms in the molecule, we find that the Δ__H__‡ values are identical, but that the value of Δ__S__‡ is 0.8 eu/mole higher for the reaction in the amines as compared with the alcohol. The rate constant, at all temperatures, is 1.5 times as large in the amine as it is in the corresponding alcohol. Empirical equations are deduced relating the parameters Δ__H__‡ Δ__S__‡ Δ__G__‡ and k of the reaction to the parameters n and T, where n is the total number of carbon atoms in the solvent molecule and T is the absolute temperature. The results reported herein are compared with previously reported data for malonic acid.