KINETIC ASPECTS OF 3, 4 dihydropyrano [c] chromenes FORMATION IN THE PRESENCE OF DIFFERENT CATALYSTS: A MECHANISTIC INVESTIGATION

摘要: A kinetic study of reaction between benzaldehyde, malononitrile and 4-hydroxycoumarin compounds has been established spectrally in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) and sodium acetate as a catalyst. Based on the experiment data, reaction followed second order rate law. The rate law that deduced from the mechanism was compatible with the observed rate law. The results showed that the first step of the reaction mechanism was a rate-determining step. Experimental effects of catalysts, solvent, concentration and functional group (structural effect) on the reaction rate provided useful information regarding the mechanism of reaction.