Kinetics and Mechanism of Tetrahydrobenzo [b] pyran Derivatives Catalyzed by Glycine as Inorganic compound

In the present investigation, the reaction between malonitrile and dimedon with derivatives of benzaldehyde have been studied spectrophotometrically for the one-pot Tetrahydrobenzo [b] pyran derivatives in the presence of glycine as a catalyst at different temperatures. The special advantages of is neutral and mild environmental conditions, lack of toxicity, giving high to excellent yields of products [1-2]. Experimentally, the reactions were found to be of secondorder and observed rate constants were determined using UV-vis spectrophotometry. The proposed mechanism was adapted in accord with the experimental results and the steady-state assumption. Kinetic values (k and Ea) and associated activation parameters (ΔG?≠. ΔS?≠and ΔH?≠) of the reactions were determined [3]. Furthermore, from studying the effect of solvent, concentration and catalyst on the reaction mechanism, useful information was obtained.