Full kinetics and a mechanistic investigation of three-component reaction catalyzed by sodium acetate leading to 3,4-dihydropyrano[c]chromene

摘要

Sodium acetate was applied as an efficient catalyst for the one-pot, three-component condensation reaction consisting of 4-nitrobenzaldehyde 2, malononitrile 3, and 4-hydroxycoumarin 1. For the first time, the kinetics and mechanism of the reaction has been investigated spectrally. The second-order rate constant dependency on the temperature was in agreement with the Arrhenius and Eyring equations. The kinetic and thermodynamic parameters of the reaction were calculated. Furthermore, useful information was obtained from studies of the solvent and concentration effects on the reaction rate. The results showed that the second step of the reaction mechanism is a rate-determining step. The proposed mechanism was also confirmed according to the obtained results and the steady-state approximation.