Synthesis of heterocyclic compounds using Vilsmeier reagent

The classical Vilsmeier reaction is a special type of Friedel-Crafts reacti on involving electrophilic substitution of suitable carbon nucleophile, wit h halomethyleniminium salt, the active intermediates in Vilsmeier reaction. Many substituted aldehyde's have been synthesized by using Vilsmeier reage nt. Numberous other possible transformations in addition to formylation hav e enhanced the scope and versatility of the Vilsmeier reaction. We have syn thesised a variety of carbocyclic and heterocyclic compounds via intramolec ular cyclization reaction using Vilsmeier reagents.