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Spectrophotometric Determination and Kinetic Studies of Condensation of Aromatic Aldehydes with 7,9‐Dioxo‐6,10‐dioxaspiro[4.5]decane
Author(s) -
Medien H. A. A.,
Zahran A. A.,
Erian A. W.
Publication year - 2004
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200400022
Subject(s) - chemistry , piperidine , decane , condensation , aldehyde , condensation reaction , reaction rate constant , chloroform , reaction rate , kinetics , order of reaction , hammett equation , medicinal chemistry , organic chemistry , catalysis , thermodynamics , physics , quantum mechanics
The condensation reaction rates of 7,9‐dioxo‐6,10‐dioxaspiro[4.5]decane with aromatic aldehydes in chloroform in the presence of piperidine has been investigated spectrophotometrically at 25–50 °C. The reaction follows overall second order kinetics, first order in each of the reactants and zero order with respect to piperidine. The rate of condensation increases with the presence of electron withdrawing groups on the aromatic ring of the aldehyde. From the dependence of the rate constants on temperature, activation parameters have been calculated. Plot of ΔH# versus ΔS# for the reaction gave a good straight line with an isokinetic temperature of 367.55 K. Based on this reaction, determination often aromatic aldehydes in a concentration range of 2.65–69.2 μg/mL is proposed.