The processes used by academic and industrial scientists to discover new drugs have recently experienced a true renaissance, with many new and exciting techniques being developed over the past 5–10 years alone. Drug design and discovery, and the search for new safe and well-tolerated compounds, as well as the ineffectiveness of existing therapies, and society’s insufficient knowledge concerning the prophylactics and pharmacotherapy of the most common diseases today, comprise a serious challenge. This can influence not only the quality of human life, but also the health of whole societies, which became evident during the COVID-19 pandemic. In general, the process of drug development consists of three main stages: drug discovery, preclinical development using cell-based and animal models/tests, clinical trials on humans and, finally, forward moving toward the step of obtaining regulatory approval, in order to market the potential drug. In this review, we will attempt to outline the first three most important consecutive phases in drug design and development, based on the experience of three cooperating and complementary academic centers of the Visegrád group; i.e., Medical University of Lublin, Poland, Masaryk University of Brno, Czech Republic, and Comenius University Bratislava, Slovak Republic.

An efficient and simple methodology for Ullmann Cu(I)-catalyzed synthesis of di- and trisubstituted 1,3,5-triazine derivatives from dichlorotriazinyl benzenesulfonamide and corresponding nucleophiles is reported. Cations Cu(I) supported on macroporous and weakly acidic, low-cost industrial resin of polyacrylate type were used as a catalyst. The reaction times and yields were compared with traditional synthetic methods for synthesis of substituted 1,3,5-triazine derivatives via nucleophilic substitution of chlorine atoms in dichlorotriazinyl benzenesulfonamide. It was found that Ullmann-type reactions provide significantly shortened reaction times and, in some cases, also higher yields. Finally, trisubstituted s-triazine derivatives were effectively prepared via Ullmann-type reaction in a one-pot synthetic design. Six new s-triazine derivatives with potential biological activity were prepared and characterized.

A series of 1,3,5-triazinyl aminobenzenesulfonamides substituted by aminoalcohol, aminostilbene, and aminochalcone structural motifs was synthesized as potential human carbonic anhydrase (hCA) inhibitors. The compounds were evaluated on their inhibition of tumor-associated hCA IX and hCA XII, hCA VII isoenzyme present in the brain, and physiologically important hCA I and hCA II. While the test compounds had only a negligible effect on physiologically important isoenzymes, many of the studied compounds significantly affected the hCA IX isoenzyme. Several compounds showed activity against hCA XII; (E)-4-{2-[(4-[(2,3-dihydroxypropyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (31) and (E)-4-{2-[(4-[(4-hydroxyphenyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (32) were the most effective inhibitors with K_Is = 4.4 and 5.9 nM, respectively. In addition, the compounds were tested against vancomycin-resistant Enterococcus faecalis (VRE) isolates. (E)-4-[2-({4-[(4-cinnamoylphenyl)amino]-6-[(4-hydroxyphenyl)amino]-1,3,5-triazin-2-yl}amino)ethyl]benzenesulfonamide (21) (MIC = 26.33 µM) and derivative 32 (MIC range 13.80–55.20 µM) demonstrated the highest activity against all tested strains. The most active compounds were evaluated for their cytotoxicity against the Human Colorectal Tumor Cell Line (HCT116 p53 +/+). Only 4,4’-[(6-chloro-1,3,5-triazin-2,4-diyl)bis(iminomethylene)]dibenzenesulfonamide (7) and compound 32 demonstrated an IC₅₀ of ca. 6.5 μM; otherwise, the other selected derivatives did not show toxicity at concentrations up to 50 µM. The molecular modeling and docking of active compounds into various hCA isoenzymes, including bacterial carbonic anhydrase, specifically α-CA present in VRE, was performed to try to outline a possible mechanism of selective anti-VRE activity.

One of the possibilities to sophisticate compound syntheses is catalysis using supported catalyst which combines the advantages of both homogeneous and heterogeneous catalyst. An application of Ce(III) inorganic salts, first of all CeCl3.7H2O doped by sodium iodide, not until has been described from start of 21st Century. Twenty communications has been present during this time only. Catalysis by Ce(III) salts has been used for an activation of carbonyl compounds and their derivatives in syntheses. Easily available, cheap and mechanically and thermally stable industrial cation-exchangers may be used as carriers1. These in connection with complex of cerium in oxidation state of 3+ provide an effective, easily separable and recyclable catalytic system. This system has been studied with a view to its possible synthetic applications on model three-component domino syntheses, i.e. Kabachnik-Fields one-pot synthesis of α-aminophosphonates2, and Prins-Ritter one-pot synthesis of 4-amidotetrahydropyran derivatives3, respectively. It has been discovered that cation Ce(III) supported on a weak acid macroporous cation-exchanger has shown in the studied reactions at least the same or better catalytic activity as salt CeCl3.7H2O, eventually doped by NaI.

Alzheimer’s disease (AD) is a multifactorial neurological disease of unknown etiology that is associated with various risk factors. Various pharmacological approaches targeting distinct mechanisms have been investigated; however, they have not yet achieved disease-modifying effects. A series of nine trisubstituted 1,3,5-triazine-based derivatives was investigated as potential inhibitors of the β-secretase enzyme (beta-site amyloid precursor protein-cleaving enzyme 1, BACE1), one of the key enzymes in the pathogenesis of AD. Although the triazine-based derivatives are reported to be potent BACE1 inhibitors, the compounds discussed in this contribution, at a concentration of 10 µM, demonstrated completely insignificant activity. It is worth noting that methyl (4-{4-[(2,3-dihydroxypropyl)amino]-6-[(4-sulfamoylbenzyl)amino]-1,3,5-triazin-2-yl}piperazin-1-yl)- acetate and 4-({4-chloro-6-[(3-hydroxypropyl)amino]-1,3,5-triazin-2-yl}amino)benzenesulfonamide showed an approximately 9% and 2% inhibition of BACE1 activity, respectively.

Synthesis of a novel 1,3,5-triazine derivatives, starting from cyanuric chloride, is reported. Target structural motives are involved in the s-triazine skeleton via substitution of chlorine atoms by amino group in various aminobenzensulfonamides, piperazines, amino alcoholes and other amino compounds. It was found that substitution of the chlorine atoms of cyanuric chloride can be carried out as C-N coupling catalyzed by Cu(I) supported on weakly acidic macroporous cation exchanger resin of polyacrylate type via the oxidative addition - heterolytic addition - reductive elimination processes. The reaction could proceed as a one-pot/ one-step synthetic process that is carried out under temperature control. Higher and excellent yields with shorter reaction times in comparison with similar usual syntheses realized step by step were obtained. Synthetic procedures optimized by this way can be applied in the preparation of the further various s-triazine with respect to the chemical behaviour of the individual nucleophilic reagents.