Facile synthesis of substituted mono-, di-, tri- and tetra-2-aryl-2,3-dihydro-1H-perimidines

The efficient synthesis of a variety of substituted 2-aryl-2,3-dihydro-1H-perimidines using Zn-catalysis is reported. A series of 2,3-dihydroperimidines with various functional groups have been isolated in high yield by simple filtration from the reaction mixture. The new compounds have been fully characterized by spectroscopic and spectrometric analyses and in some cases also by X-ray diffraction. The synthetic approach was subsequently also tested for di-, tri-, and tetra-(salicyl)aldehyde reagents and afforded the corresponding multi-perimidines in good yields. In the present studies also an unexpected bis(2,3-dihydro-1H-perimidine) decomposition product has been identified. The current approach underlines the simplicity of creating a series of perimidines which may be post-altered by using the functional group diversity introduced through the aldehyde reagents.