Suman Thummanagoti
Traceless synthesis of 2-aminoimidazoquinoxalinones has been performed on soluble polymer support under openvessel microwave dielectric heating. The reaction progression is monitored directly by the conventional proton Nuclear Magnetic Resonance (NMR) without release of the substrate from the support. Fmoc-deprotected amino acid polymer conjugates react with 1,5-difluoro-2,4-dinitro benzene to yield polymer bound dinitro fluoro amines, which are further substituted by various primary amines to yield PEG-immobilized dinitro diamines. Simultaneous reduction of aromatic meta-dinitro group leads to the traceless release of 2-qunoxalinones, followed by N-hetero cyclization with various isothiocyanates in the presence of mercury (II) chloride to furnish 2-aminoimidazoquinolinone rings with three points of diversity at rapid pace.