7-(Imidazolidin-1-ylmethyl)quinoline-8-ol, an N-substituted imidazolidine, was synthesized in a one-step reaction between 1,3,6,8-tetraazatricyclo[4.4.1.1 3,8 ]dodecane (TATD) and 8-hydroxyquinoline.Obtaining this substance enhanced the scope of possibilities in the synthesis of unsymmetrically N,N-disubstituted imidazolidines. 1 H-NMR spectral studies revealed that this type of substance does not undergo ring-chain tautomerism.In the course of our research into Mannich-type reactions in basic medium between macrocyclic aminals and nucleophiles, we developed an ortho-regioselective method for preparing 1,3-bis(2'-hydroxy-5'-substitutedbenzyl)imidazolidines (BISBIAs) from 1,3,6,8-tetraazatricyclo-[4.4.1.1 3,8 ]dodecane (TATD) (1) and phenols, 1 using the concept of inter-and intramolecular hydrogen bonding to explain the ortho-regioselectivity of this reaction.In order to analyze the effect of intramolecular hydrogen-bonding acceptor sites, we decided to carry out some reactions between 1 not only with 8-hydroxyquinoline (2) and 2-subsituted phenols with hydrogen bond acceptor groups, such as o-nitrophenol, salicylaldehyde and 2-hydroxy-4-methoxy-acetophenone, but also with oxine π-isoelectronic systems, such as αand β-naphthol.Intramolecular hydrogen bond formation in 2 and in the above mentioned phenols is of special interest, because this hydrogen bond induces important changes in their reactivity.In this paper we report on the exclusive and preferential reaction between 1 and 2 to give an unsymmetrical imidazolidine (3) (Scheme 1).Although many methods have been described in the literature for obtaining symmetrically N,N-disubstituted imidazolidines there are few reports concerning the synthesis of unsymmetrical substituted imidazolidines 2-6 and only one on N-monobenzylimidazolidines. 7It is noteworthy that the development of mild and efficient methods to obtain this heterocyclic systems has been