Visible light induced acridinium catalysed synthesis of potentially bioactive spiropyrazolones

A visible-light-mediated an effective organocatalytic synthesis of bioactive spiropyrazolones has been described here. This photoredox synthetic approach includes metal free acridinium catalysed cycloaddition reaction between benzylidene-pyrazol and benzylidenepentenal to give the desired product with high yield and wide functional group tolerance under mild conditions.