Kinetics and related studies of the formation of 2,3‐dihydroquinazolin‐4(1H)‐ones in the presence of different benzaldehyde derivatives

The kinetics and activation parameters for the reaction between 2‐amino‐benzamide and some benzaldehyde derivatives in the presence of formic acid have been reported and discussed. A linear plot of lnk vs l/T showed that the reactions obey the Arrhenius equation. Both the Arrhenius and the Eyring equations were used to calculate the activation energy. The effect of nitro groups was studied on different positions of benzaldehyde. For all substituents, the reactions followed second‐order kinetics, and the partial orders of reactions were recognized with respect to each reactant. Comparisons between the magnitudes of ΔH‡ and TΔS‡showed that the reactions were enthalpy controlled. The validity of the isokinetic relationship and the compensation effect was tested, and the isokinetic temperature (β) was obtained. A linear enthalpy‐entropy plot (ΔH‡versusΔS‡) showed that the compensation effect is established, and this process occurs via a same mechanism across a series of reactions. From the Van't Hoff and Exner's plots, the isokinetic temperature was obtained. Herein, we investigate the validity of the isokinetic relationship and compensation effect in addition to the kinetic studies.