| Abstract [eng] |
Pyrazoles and their heteroannulated derivatives are an important part in organic and medicinal chemistry. They exhibit anti-cancer, anti-diabetic, anti-viral, anti-inflammatory, anti-bacterial, anti-fungal, anthelmintic, antimalarial, photosensitizing, dyeing and fluorescence properties. Pyrazolopyridines are among the most studied annealed pyrazole systems in organic and pharmaceutical chemistry. Thus the aim of this work is to prepare a library of functionalized 2H-pyrazolo[4,3-c]pyridines by employing ring closing and palladium catalyzed cross-coupling reactions and to investigate and analyse their properties. In this work, 4,7-disubstituted 2,6-diphenyl-2H-pyrazolo[4,3-c]pyridines have been synthesized from 1-phenyl-1H-pyrazol-3-ol via 1-phenyl-3-(phenylethynyl)-1H-pyrazole-4-carbaldehyde which was converted into 4-substituted-7-iodo-2H-pyrazolo[4,3-c]pyridines during a three-step procedure. Substituents to the 7-position were introduced by using palladium catalyzed cross-coupling reactions (Suzuki-Miyaura, Buchwald-Hartwig, Heck). All the derivatives exhibited different optical and biological properties with interesting and potent applications: 7-(4-methoxyphenyl)-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridine showed potential fluorescent pH sensing, 4-(2,6-diphenyl-2H-pyrazolo[4,3-c]pyridin-7-yl)phenol displayed antiproliferative activity against MV4-11, K562 and MCF-7 cancer cells, while N-aryl-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridin-7-amines and 2,6-diphenyl-7-[(E)-2-phenylethenyl]-2H-pyrazolo[4,3-c]pyridines exhibited photosensitizing properties for photodynamic therapy against G361 melanoma cancer cells. |
