Antimicrobial and Physicochemical Characterizations of Thiosemicarbazide and S-Triazole Derivatives

Chemodivergent Photocatalyzed Heterocyclization of Hydrazones and Isothiocyanates for the Selectivity Synthesis of 2-Amino-1,3,4-thiadiazoles and 1,2,4-Triazole-3-thiones

A photocatalytic chemodivergent reaction for the selectivity formation of C-S and C-N bonds in a controlled manner was proposed. The reaction medium, either neutral or acidic, is critical to dictate the formation of 2-amino-1,3,4-thiadiazoles and 1,2,4-triazole-3-thiones from isothiocyanates and hydrazones. This is a practical protocol to achieve the chemoselectivity under mild and metal-free conditions.

4-(4-Chlorophenyl)-4,5-dihydro-1H-1,2,4-triazole-5-thione

The title compound, 4-(4-chlorophenyl)-4,5-dihydro-1H-1,2,4-triazole-5-thione (1), was synthesized by a hetero-cyclization reaction of 4-chlorophenyl isothiocyanate and formic hydrazide. Compound 1 was characterized by a single-crystal X-ray structure determination as well as 1H and 13C{1H} NMR, IR, and UV spectroscopy, and microelemental analysis. X-ray crystallography on 1 confirms the molecule exists as the thione tautomer and shows the five-membered ring to be planar and to form a dihedral angle of 82.70(5)° with the appended chlorophenyl ring, indicating an almost orthogonal relationship. In the molecular packing, supramolecular dimers are formed via thioamide-N–H⋯S(thione) hydrogen bonds and these are connected by C=S⋯π(triazolyl) and C-Cl⋯π(triazolyl) interactions, leading to a three-dimensional architecture.

Synthesis, molecular modeling and anticancer activity of new coumarin containing compounds

A series of new coumarin containing compounds were synthesized from 4-bromomethylcoumarin derivatives 2a, b and different heteroaromatic systems 4a-e, 6a-d, 8, 10via methylene thiolinker. Twenty-four compounds were screened biologically against two human tumor cell lines, breast carcinoma MCF-7 and hepatocellular carcinoma HePG-2, at the national cancer institute, Cairo, Egypt using 5-fluorouracil as standard drug. Compounds 5h, 7d, 7h, 9a, 13a and 13d showed strong activity against both MCF-7 and HepG-2 cell lines with being compound 13a is the most active with IC₅₀ values of 5.5 µg/ml and 6.9 µg/ml respectively. Docking was performed with protein 1KE9 to study the binding mode of the designed compounds.

Telescoped continuous flow generation of a library of highly substituted 3-thio-1,2,4-triazoles

An integrated continuous flow process for the synthesis of 3-thio-1,2,4-triazoles is reported. A small library of 18 compounds was prepared in just 48 minutes of residence time in moderate to excellent yields.