Sucrose is applied as an efficient catalyst for the three-component reaction consisting of aromatic aldehydes, malononitrile and resorcinol in a mixture of water and ethanol media as green solvents. The advantages of this method are excellent yeild, inexpensive catalyst and more environmentally friendly. Mechanistic insight into the synthesis of 2-amino-4H-chromene included spectral kinetics approaches is revealed. From the temperature, concentration and solvent studies, the activation energy (Ea=102 kJmol-1) and the related kinetic parameters (ΔGǂ=41 kJmol-1, ΔSǂ=195 Jmol-1 and ΔHǂ=99 kJ mol-1) are calculated. The first step of proposed mechanism is recognized as a rate-determining step (k1) and this is confirmed based upon the steady-state approximation. پرونده مقاله

Acetic acid has been applied as an efficient catalyst and a green solvent for the two–component condensation reaction consisting of benzaldehyde, 2-amino-benzamide. The advantages of this protocol was excellent yield, short reaction time, mild reaction conditions, higher availability, low costs, more environmentally friendly, lack of need for column chromatography and simple work-up procedure. In addition, based on the spectral data, the partial order with respect to each reactant was one. Furthermore, useful information regarding the mechanism of the reaction was obtained from studies of the effect of solvent, concentration and catalyst on the rate of the reaction. The results showed that the first step of the mechanism was a rate-determining step. In the studied temperature range, the second order rate constant (lnk1, lnk1/T) depended on reciprocal temperature was in good agreement with the Arrhenius and Eyring equations. These data provided the suitable plots for calculating the activation energy (Ea = 52.80 kJmol-1) and the related kinetic parameters (ΔG‡ = 63.74 kJmol-1, ΔS‡ = -54.22 Jmol-1 and ΔH‡ = 50.28 kJmol-1) of the reaction. پرونده مقاله