Suman Thummanagoti*
In this paper we have explored an ionic liquid as a matrix liquid to generate small molecule library on homogeneous phase soluble medium. In this context a rapid and effective method to prepare various isoindolo (2,l-a) benzimidazolone, pyrrolo (1,2-a) benzimidazolone and pyrido (1,2-a) benzimidazolone libraries on ionic liquid support by using focused microwave irradiation was described. The 4-fluoro-3-nitrobenzoic acid has been used as a building block to generate the benzimidazole heterocyclic core for library diversity through the ionic liquid supported multistep synthesis. Thereby various primary amines have been used to displace the fluorine atom through the nucleophilic substitution and subsequent reduction led to the IL supported conjugate diamine. The obtained conjugate diamne used as a scaffold to generate various ring size heterocyclic libraries via one pot intermolecular condensation with various substituent aliphatic γ and δ ketoacids in the presence of catalytic trifluoroaceticacid under microwave irradiation. This tandem operational simplicity procedure was extended to the aromatic γ and δ ketoacids, provided structurally heterogeneous libraries with skeletal diversity. The aforementioned three classes of heterocyclic lactam compounds further converted to thiolactams by using lawesson’s reagent. The relative high yield and purities with two points of diversity was reported.