Heterocyclizations under Vilsmeier conditions: an old method with interesting possibilities in drug research.

The Vilsmeier reaction is well known and widely used in substituting activated hydrogen with a formyl group into a great variety of mols.  This reaction is also a powerful synthetic tool used to obtain many heterocycle compds., which may be difficult to reach or at times inaccessible.  The more relevant data published in chem. literature in the last ten years and my personal experience are reported in the following with the aim of showing the valuable synthetic potential of this reaction.