A novel approach toward the synthesis of some new tridentate Schiff bases from anil-like compounds

Abstract

A novel method was developed for synthesizing a series of new tridentate Schiff base ligands starting from hydroxynaphthyl pyrimidinyl amines with o-phenylenediamines or o-aminophenol or 2-amino-3-hydroxy-pyridine in the presence of formic acid catalyst under solvent-free conditions. In these reactions [1+1], the condensation product as half-unit ligand was obtained. Moreover, the reaction of hydroxynaphthylmethylene pyrimidinyl amines with 3,4-diaminopyridine and 1,8-naphthalenediamine leads to the formation of C2-naphthylated imidazopyridine and dihydropyrimidine, respectively. The attractive features of this protocol are use of an inexpensive catalyst, operational simplicity, short reaction times, easy handling, and good yields.