A new biologically active molecular scaffold: crystal structure of 7-(3-hydroxyphenyl)-4-methyl-2H-[1,2,4]triazolo[3,2-c][1,2,4]triazole and selective antiproliferative activity of three isomeric triazolo–triazoles

Abstract

A study of three isomeric compounds containing a phenolic moiety attached to the nitrogen‐rich triazolo–triazole bicycle is presented. In the three isomers, the phenolic OH group is in the ortho, meta and para positions. The crystal structure analysis of the meta isomer (C10H9N5O) shows that the 2H‐tautomer is present in the crystal and that the molecule adopts a substantially planar geometry. However, the conformation found in the crystal is different compared to the monoprotonated cation of the same compound previously investigated in several salts. The packing of the meta isomer is driven by the formation of strong hydrogen bonds and shows the formation of infinite planar ribbons, parallel to a, formed around 21 crystallographic axes. The three isomers were tested against some cancer cell lines and also against normal cell lines. The ortho isomer shows a weak antiproliferative activity, the meta isomer shows significant antiproliferative activity against some cancer lines and no activity against healthy cell lines, and the para isomer is active against all the tested cell lines.

Synthesis and Crystallization of N-Rich Triazole Compounds

“…These These two occurrences account for no more than 0.5% of molecules in the Cambridge Structural Database, which is another reason why quasi-degenerate tautomeric systems are particularly interesting. In recent years, our focus has been directed toward the synthesis and examination of benzimidazole [20][21][22] and N-rich triazole derivatives [7,12,16,17,23] in order to investigate their chemico-physical properties and tautomerism. Here, we report the synthesis and crystallization of five novel N-rich triazole systems with a nitrogen content between 55 and 70% w/w, which are potentially of interest for HEDMs applications (Scheme 1).…”