Synthesis of novel pyrimido pyrimidin using ionic liquid as catalyst

Pyrimido pyrimidin are important compounds because of their biological properties whichare known to depend mainly on the nature and position of the substituent [ 1]. Pyrimidopyrimidin derivatives display a broad range of biological activities such as antineoplastic[2-3], antiviral [4], antibiotic [5] and anti-inflammatory [6] including other biologicalactivities. Pyrimidines exhibit a range of pharmacological activity such as antibacterial [7],antifungal [8], anticancer [9], anti-inflammatory [10] and cardioprotective effects [11].Following our continued interests in the synthesis of biologically important heterocycles inthis research, we wish to report a very simple and highly efficient one-pot method for thesynthesis of novel pyrimido pyrimidin via a three-component cyclo condensation ofequimolar amounts of 1,3-indanedione ،aromatic aldehydes and 6-amino-2-(ethylthio)pyrimidin-4(3H)-one derivatives in the presence of ionic liquid [hmim][HSO4] (Scheme 1). This efficient method furnished the desired products (4a-f) in high yields (85-97%) andreaction times (20-50 min). High yields and ease of recovery and reusability of ionic liquidwith consistent activity, makes this protocol efficient and environmentally benign.