Structure and Solution Equilibrium of N-Salicylidene-amino-sugars and Amino-alcohols.

抄録

The structures and solution equilibria of twenty members of N-salicylidene-amino-sugars and -amino-alcohols were examined mainly in methanol, water and solid state. As the modeled compounds were examined simultaneously three members of N-salicylidene-alkylamines and eight members belonged to the o-methoxybenzylidene, 3-methoxysalicylidene, 3, 5-dibromosalicylidene and 2-hydroxynaphthylidene derivatives. From the comparative studies on the electronic, infrared, NMR spectra and equilibrium position, it was shown that the solution equilibrium consisted of the phenolimine and the ketoamine species, the latter being stabilized by the intra- and intermolecular hydrogen bonding involving the alcoholic hydroxyl groups and protic solvents. The acid-base equilibria of the two tautomers in methanol and the ketoamine-ion-pair equilibrium in water were discussed.