The gas-phase elimination kinetics of ethyl 2-furoate and ethyl 2-thiophenecarboxylate

✍ Scribed by Liliany Espitia; Ruby Meneses; Rosa M. Dominguez; Maria Tosta; Armando Herize; Jesus Lezama; Jennifer Lafont; Gabriel Chuchani

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 158 KB
• Volume: 41
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20382

✦ Synopsis

Abstract

The gas‐phase elimination kinetics of ethyl 2‐furoate and 2‐ethyl 2‐thiophenecarboxylate was carried out in a static reaction system over the temperature range of 623.15–683.15 K (350–410°C) and pressure range of 30–113 Torr. The reactions proved to be homogeneous, unimolecular, and obey a first‐order rate law. The rate coefficients are expressed by the following Arrhenius equations: ethyl 2‐furoate, log k~1~ (s^−1^) = (11.51 ± 0.17)–(185.6 ± 2.2) kJ mol^−1^ (2.303 RT)^−1^; ethyl 2‐thiophenecarboxylate, log k~1~ (s^−1^) = (11.59 ± 0.19)–(183.8 ± 2.4) kJ mol^−1^ (2.303 RT)^−1^. The elimination products are ethylene and the corresponding heteroaromatic 2‐carboxylic acid. However, as the reaction temperature increases, the intermediate heteroaromatic carboxylic acid products slowly decarboxylate to give the corresponding heteroaromatic furan and thiophene, respectively. The mechanisms of these reactions are suggested and described. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 145–152, 2009