Abstract
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 degreesC. 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 DeltaH(#) versus DeltaS(#) for the reaction gave a good straight line with an isokinetic temperature of 367.55 K. Based on this reaction, determination of ten aromatic aldehydes in a concentration range of 2.65-69.2 mug/mL is proposed.