Synthesis of Heteroatom Substituted Naphthoporphyrazine Derivatives with Near-Infrared Absorption and Emission

In an effort to develop effective new optical contrast agents, we report the synthesis of porphyrazines (pzs) of the form H2[pz(A4−n;Cn)], n = 1, and 2 (trans-), where “A” represents peripheral heteroatom (S- and O-) R-groups and “C” is a fused, β,β′-diisopropyloxynaphtho group. The sulfide appended trans-H2[pz(A2;C2)] pz (7) has the longest wavelength absorption, ∼874 nm (log ε = 4.53), and S1 fluorescence at ∼927 nm, wavelengths within the window of maximum tissue penetration. Emission from the oxygen-atom appended naphtho-pzs (8, 9) has been observed within carcinoma cells, confirming cellular uptake and their potential use as optical agents.