Synthesis and characterization of asymmetric oxyacetamide bridged porphyrin conjugates embedded with N-containing heterocycles

Abstract

In the search for photosensitizers based on 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (m-THPP, 1), a novel series of asymmetric A3B porphyrin molecules with oxyacetamide linkers have been synthesized. A facile synthetic route was followed through the reaction of m-THPP derived porphyrin monoacid with amino-heterocyclic molecules in the presence of HBTU/DIPEA coupling reagent to obtain the respective porphyrin conjugates 7-10, 16, 18 in satisfactory yields 30–76%. The structures of all compounds were confirmed by the means of 1H, [Formula: see text]C NMR and by mass spectrometry (MALDI-TOF). The absorption and emission spectra of the synthesized porphyrin conjugates were displayed in methanol and showed high extension coefficient values. These preliminary studies could qualify these new candidates in being added to the porphyrin library for photomedicine applications.