A number of 2-(α-amino-Y-substituted-benzyl)-1-naphthol hydrochlorides were prepared by a convenient Mannich-type aminoalkylation. 2,4-Diaryl-3,4-dihydro-2H-naphth-[2,1-e][1,3]oxazines were prepared through the ring-closure reactions of the starting aminonaphthols with aromatic aldehydes, which proved to furnish three-component (ring1-open-ring2) tautomeric mixtures in CDCl3 at 300 K. The electronic effects of the 2-aryl groups on the ratios of the ring-chain tautomeric forms at equilibrium could be described by Equation (1). Study of the effects of substituents X and Y on the tautomeric equilibria [by the aid of the multiple linear regression analysis of Equations (2) and (3)] revealed that the trans-chain equilibrium constants are significantly influenced by the inductive effect (σF) of substituent Y on the 4-phenyl ring.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry