Synthesis of Chlorophyllous Chlorins Derivatives Substituted by Aromatic Groups on Their Periphery

Pyropheophorbide-a methyl ester, as a degraded product from chlorophyll-a, was used as a starting material, and the modifications for functional group along N-21-N-23-axis and reconstructions for five-membered exocyclic E-ring were completed to introduce different aromatic groups which could conjugated with macrocyclic chromophore at various degrees on the periphery. The syntheses of 12 unreported chlorins related to chlorophyll were accomplished and their chemical structures were characterized by elemental analysis, UV, IR, MS and H-1 NMR spectra. The different effects on the physical and chemical properties of chlorophyllous chlorins by introduction of aromatic groups were discussed.