Facile synthesis of N,Nʹ-diarylformamidines by acidic ionic liquid immobilized on nanoporous TiO2

Formamidines are one of the noteworthy classes of compounds because they have a wide range of biological and pharmacological properties. For example they have been used as pesticides and antimalarial reagents [1-2]. The general procedure for the preparation of formamidines involves the reaction between two moles of aniline derivatives with one mole of ethyl orthoformate in the presence of an organic or mineral acid catalyst [3]. Various methods have been proposed for this reaction, but some of the have disadvantages, including the use of homogeneous catalysts that have several serious problems. In this work, a green and efficient procedure is reported for the preparation of N,N - diarylformamidines using acidic ionic liquid immobilized on nanoporous TiO2. The procedure gave the products in excellent yields in very short reaction times undersolvent-free conditions. The reusability of the catalyst is the other important feature of the reported method