Catalyst-free synthesis of highly functionalized triazole hexahydroquinoline carbohydrazide scaffolds via four-component cyclocondensation reaction

A new class of multi-functional triazole hexahydroquinoline carbohydrazide named 2-amino-7,7-dimethyl-5-oxo-4-phenyl-1-(4H-1,2,4-triazol-3-yl)-1,4,5,6,7,8-hexahydroquinoline-3-carbohydrazide has been synthesized by a novel multi-component process involving the reaction of dimedone, 3-amino-1,2,4-triazole, various benzaldehyde with cyanoacetohydrazide under mild conditions in the stoichiometric melt and chloroform in sequence. The simple one-pot process, straight product isolation without applying tedious purification procedures, progression of the reaction without using any catalyst, the application of diverse aldehydes causing a high molecular diversity, the existence of several nitrogen atoms in the product structure, and the possibility of creating multiple hydrogen bonding in the final compound are attractive specifications of the present strategy.

Hantzsch-Like Synthesis, DNA Photocleavage, DNA/BSA Binding, and Molecular Docking Studies of Bis(sulfanediyl)bis(tetrahydro-5-deazaflavin) Analogs Linked to Naphthalene Core

The cyclocondensation reaction of aldehydes with dimedone and bis(6-aminopyrimidin-4-one) in acetic acid led to the formation of the corresponding bis(pyrimido[4,5-b]quinoline-4,6-diones) which are known as bis(sulfanediyl)bis(tetrahydro-5-deazaflavin) analogs in a single step. Also, bis(pyrimido[4,5-b]quinoline-4,6-diones) which are linked to naphthyl core via phenoxymethyl linkage is prepared. The interactions of the synthesized compounds with DNA and bovine serum albumin (BSA) were studied. Gel electrophoresis assay was used to show the capability of the compounds to photocleave the supercoiled pBR322 plasmid DNA in UV-A (365 nm). Besides, the most photocleavable compound, bis(tetrahydropyrimido[4,5-b]quinoline-4,6-dione) linked to pyridin-3-yl at position-5 exhibits good binding affinities toward CT-DNA and BSA as supported by UV/VIS spectral studies. In addition to the experimental findings, a molecular docking simulation was performed to collect detailed binding data for this compound to both biomolecules.

Synthesis and characterization of novel bis(pyridine-2(1H)-thiones) and their bis(2-methylsulfanylpyridines) incorporating 2,6-dibromophenoxy moiety

The novel 1,4-bis(2,6-dibromo-4-formylphenoxy)butane (3), prepared from 3,5-dibromobenzaldehyde (1), reacted with different hydrazines 4a–4d and active methylene containing compounds 9a–9d to give the corresponding bis(hydrazones) 5a–5d and bis(cinnamonitriles) 11a–11d, respectively. Both bis(2-cyanoacetic acid hydrazide) derivative 5d and bis(thioacrylamide) derivative 11a were taken as synthetic precursors for the synthesis of the target molecules bis(pyridine-2(1H)-thione) derivative 10 and 13a–13c and their bis(2-methylsulfanylpyridine) derivative 14 and 17a–17c. Another synthetic route was designed to prepare the target molecules 14 and 17a–17c in a better yield using pyridine-2(1H)-thione) derivative 15 and 19a–19c. Characterization of the newly prepared compounds via elemental analyses and spectral data are established.