Kinetic Aspects of Tetrahydrobenzo[B]Pyran Formation in The Presence of Agar as A Green Catalyst: A Mechanistic Investigation
Mehdi Shahraki*, Sayyed Mostafa Habibi-Khorassani and Sayyedeh Shadfar Pourpanah
Department of Chemistry, University of Sistan and Baluchestan, P.O.Box 98135-674, Zahedan, Iran.
Corresponding Author E-mail: mehdishahraki@chem.usb.ac.ir
DOI : http://dx.doi.org/10.13005/bbra/2090
ABSTRACT: The kinetic and mechanism of the reaction between benzaldehyde, malononitrile and dimedone has been studied in the presence agar as a highly efficient homogenous catalyst in a mixture of (water/ethanol, 2:1). Based on the experiment data, the overall order of reaction for the formation of tetrahydrobenzo[b]pyran followed second-order kinetics and under pseudo-order conditions the partial orders with respect to 1, 2 and 3 were one, one and zero, respectively. From the temperature, concentration and solvent studies, the activation energy (Ea) and the related kinetic parameters (ΔG‡, ΔS‡ and ΔH‡) are calculated. The first step of the proposed mechanism is recognized as a rate-determining step (k1) and this is proved by the steady state approximation.
KEYWORDS: Kinetics;Mechanism;Tetrahydrobenzo[b]pyran;Agar;Catalyst
Download this article as:Copy the following to cite this article: Shahraki M, Habibi-Khorassani S. M, Pourpanah S. S. Kinetic Aspects of Tetrahydrobenzo[B]Pyran Formation in The Presence of Agar as A Green Catalyst: A Mechanistic Investigation. Biosci Biotech Res Asia 2016;13(2). |
Copy the following to cite this URL: Shahraki M, Habibi-Khorassani S. M, Pourpanah S. S. Kinetic Aspects of Tetrahydrobenzo[B]Pyran Formation in The Presence of Agar as A Green Catalyst: A Mechanistic Investigation. Biosci Biotech Res Asia 2016;13(2). Available from: http://https://www.biotech-asia.org/?p=14167 |