The kinetic studies on the addition of amines(primary, secondary and tertiary) to Malonic acid Benzylidene Diethyl Ester(MBDE) and Ethylcinnamate(EC) have been carried out in several solvents (MeOH, EtOH and n-PrOH) and at various temperatures.
The ...
The kinetic studies on the addition of amines(primary, secondary and tertiary) to Malonic acid Benzylidene Diethyl Ester(MBDE) and Ethylcinnamate(EC) have been carried out in several solvents (MeOH, EtOH and n-PrOH) and at various temperatures.
The order of reactivity in solvents was MeOH>eToh>N-PrOH, this result could be explained by the thermodynamic parameters and the dielectric constant of solvents.
From the kinetic data, the following reactivity of amines has been derived ; piperidine>n-butylamine>diethylamine>benzylamine.
This result was concurred with the Bronsted relationship, expect the deviation of diethylamine which might be resulted from its steric hinderance.
It was found that the 3。 amines was less reactive than that of 1。 and 2。 amines toward MBDE. It was therefore suggested that the reactivity of amines was influenced by the formation of intramolecular hydrogen bond.
The difference of reactivity between MBDA and EC could be explained by the neighboring group effect.