Catalytic Activities of Salicylaldehyde Derivatives. II. Kinetic Studies of the Racemization of Amino Acid

Publisher Website
Google Scholar
Abstract
In the racemization reaction of L-glutamic acid, catalyzed by salicylaldehyde derivatives and cupric ions, the rate constants, k, of 3-bromo-, 3-methoxy-, 3-methyl-, 3-nitro-, 4-methyl-, 5-bromo-, 5-methoxy-, 5-methyl-, and 5-nitro-salicylaldehydes and of salicylaldehyde were measured and the kinetic relation between the rate constant, k, of the salicylaldehyde derivatives and the corresponding Hammetfs constant, σ, was studied. A linear relation between logk and the σ of 4- or 5-substituted salicylaldehydes and another linear relation between logk and the σ of 3-substituted salicylaldehydes were found. The activation energies of the racemizations catalyzed by pyridoxal, 3-nitro-, and 5-nitro-salicylaldehydes and by salicylaldehyde were determined, but no distinct difference between 3-nitrosalicylaldehyde and 5-nitrosalicylaldehyde was observed.