957656-57-4

Upstream product

• 115581-88-9 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6,7-dicarbonitrile 
• 129365-93-1 4,5-diaminophthalonitrile 

Downstream Products

• 1218819-13-6 2,3-bis(2,6-diisopropylphenoxy)quinoxaline-6,7-dicarbonitrile 

Relevant academic research and scientific papers

Synthesis, properties and in vitro photodynamic activity of water-soluble azaphthalocyanines and azanaphthalocyanines

In this work zinc azaphthalocyanines (AzaPcs) from the group of tetrapyrazinoporphyrazines and zinc azanaphthalocyanines from the group of tetra[6,7]quinoxalinoporphyrazines (TQP) with eight diethylaminoethylsulfanyl substituents were synthesized. Tertiary amines were later quaternized with ethyl iodide to obtain water-soluble photosensitizers (PSs). Quaternized compounds showed high singlet oxygen quantum yields as determined in DMF by monitoring decomposition of 1,3-diphenylisobenzofuran. In water medium, quaternized AzaPc derivatives appeared in monomeric form in a wide range of concentrations while quaternized TQP derivatives showed aggregation at higher concentrations (over 1 μm). Photodynamic activity was tested on Hep2 cells using light of λ > 640 nm. Both quaternized dyes showed high photodynamic activity (IC 50 = 104 and 220 nm for AzaPc and TQP, respectively). Dark toxicity was not detected even at the highest concentration used in in vitro tests (200 μm) which indicates a promising therapeutic index of these new substances. Tested compounds localized inside the cells mainly within the lysosomes thus suggesting an endocytic mechanism of cellular uptake. No localization within mitochondria was detected. A great advantage of TQP derivatives over other PSs is their very strong absorption at 747 nm that allows activation at wavelengths penetrating deeper into human tissues.

Synthesis, separation and UV/Vis spectroscopy of pyrazino- quinoxalinoporphyrazine macrocycles

Unsymmetrical metal-free and zinc complexes of pyrazinoquinoxalino- porphyrazines (PQP) bearing eight diethylamino groups have been synthesized by statistical tetramerization of 2,3-bis(diethylamino)quinoxaline-6,7- dicarbonitrile and 5,6-bis(diethylamino)pyrazine-2,3-dicarbonitrile in lithium butanolate. For this purpose, a new heteroatom-substituted quinoxaline precursor, 2,3-dichloro-6,7-dicarbonitrile, was prepared and characterized. It is a flexible starting material for new building blocks of quinoxaline-6,7- dicarbonitrile derivatives. All the PQPs (including adjacent and opposite isomers) from the statistical mixture were detected and separated by column chromatography on silica and characterized by MALDI-TOF mass spectrometry, IR, UV/Vis and NMR spectroscopy. The effect of the insertion of benzene rings into the tetrapyrazinoporphyrazine (TPP) system is discussed. Each benzene ring insertion into the TPP system causes a bathochromic shift of 22 nm; the dependence is linear. The final tetra[6,7]quinoxalinoporphyrazines were red-shifted to 744 and 763 nm for the zinc and metal-free derivative, respectively. Splitting of the Q-band was observed for PQPs with lower symmetry. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.