Synthesis of 2-amino-5-alkylidenethiazol-4-ones from ketones, rhodanine, and amines with the aid of re-usable heterogeneous silica-pyridine based catalyst

A new methodology has been developed towards the synthesis of novel 2-amino-5-alkylidenethiazol-4-ones from ketones, amines, and rhodanine. This is the first report of the use of ketones in contrast to aldehydes in all the earlier reported procedures. A new heterogeneous dipolar catalyst is designed and synthesized for this reaction. The unique properties of this catalyst facilitate the synthesis of such compounds. These 5-alkylidene rhodanine precursors display wide range of biological activities to possess antiviral, antimicrobial, cardiotonic and anti-inflammatory effects.