In search of new thermotropic, photoswitchable materials, a number of 4′-alkoxy-4-(ω-cinnamoylalkoxy)azobenzenes were prepared. The synthetic procedure included O-alkylation of 4-nitrophenol, followed by reduction of the nitro group (H₂, Pd/C), diazotization of the aniline and subsequent reaction with ω-hydroxyalkoxybenzenes, followed by a modified Appel-type esterification (BrCCl₃, PPh₃). The photochemical behavior of the substances was investigated.

Solanum glaucophyllum is a species of the Solanaceae family widely distributed in flooded areas of natural grasslands in the northeast of Argentina. Since 1960 its consumption by cattle has been associated with cattle specific vitamin D₃ intoxication known as enzootic calcinosis disease. This particular disease is related to alteration in absorption of vitamin D₃ and actually leads to the detriment of Argentina´s livestock economy.

Concerning bibliography background, vitamin D₃ is known to be present in species belonging to the Solanaceae family and has been identified in S. glaucophyllum from the enzymatic hydrolysis of the ethanol-water extract obtained from the leaves of this species. In addition, vitamin D₃ in S. glaucophyllum showed a similar photodependent process of synthesis to the vertebrates. Inspired on thrusting forward the study S. glaucophyllum biosynthetic pathway to vitamin D₃, the aim of the present work is to provide knowledge of vitamin D₃ toxicity related to concentration in the mentioned species located throughout the Río Salado basin. Herein we present the development of a reverse phase high performance liquid chromatography (RP-HPLC) method for the determination and analysis of vitamin D₃ and its hydroxylated metabolites. An exhaustive optimization of RP-HPLC method allow us to perform calcitriol (1a,25-(OH)₂D₃) and calcidiol (25-OHD₃) identification, both metabolites obtained by chemical hydrolysis of S. glaucophyllum leaves starting off its hydrophilic extract.

These results will improve a smart design management and monitoring scheme for S. glaucophyllum, achieving a more selective control of this weed, avoiding cattle declining in the Río Salado basin.

The oxidation of alkylaromatic substrates under phase transfer catalysis conditions for obtaining carboxylic and carbonilic derivatives is reported (cetyltrilmethilamonio, MnO₄ -, CH₂Cl₂ / H₂O, range of temperatures). Reaction conditions (molar rates and relations of reagents, volumes of reaction mixture, reaction times) are detailed. Cromatographic conditions for detection and increasing the efficiency of qualitative identification of carboxi - and carbonile derivatives were analyzed by means of thin layer chromatography using silicagel chromatoplates 60G of 0,25 mm of thickness and as developing reagent a 1% vainilline solution in HClO₄ 50% or chromato-cameras with vapors of iodine. To identify carboxylic derivatives silicon and aluminum oxides were used in thin layer or mixed with starch, revealing with hydroalcoholic solutions of indicators. For detecting carbonílic compounds silicagel modified with polyethyleneglycol 4000 (30g SiO₂ + 12 g Polyethylenglycol-4000) was used. Elution is developed with a solvent mixture: CCl₄-ethanol (120:1 v/v) and the synthesized compounds revealed with iodine vapors. The experimental data allows to optimize the yield ( > 70 %) and the purification process of those derivatives. This procedure inhibits the autocatalytic process of destruction of the KMnO₄ under the reaction conditions and the adsorption of target compounds onto manganese (IV) oxide. The described procedure minimizes the production and volume of residual wastes. An hypothetical mechanism of the oxidation is proposed. The obtained compounds were properly characterized using physico-chemical methods, corroborating the proposed structures for generated acids and ketoderivatives

The classic bromination of aromatic substrates is carried out, conventionally by using of bromine, a very toxic pollutant and hazard. Its manipulation is difficult and during bromination is necessary to use expensive catalysts that generate wastes with great environmental impact.

In the last years several catalysts have been introduced but their regioselectivity is not high and require bromine for their preparation. The polyhalide (perbromide) ammonium salts like piridinium tribromide and phenyltrimethylammonium tribromide have been used as brominating agents in mild conditions. These reagents can be used quantitatively in solid form, which facilitates their manipulation at laboratory scale. In the present communication a synthetic way for obtaining bromophenol derivatives using as brominating agent benzalkonium tribromide (Benzal-Br3) is reported. This compound is obtained starting from commercially available benzalkonium chloride and its treatment with NaBrO3-HBr in dichlorometane under simple conditions and with satisfactory yields. Its structural and physic-chemical characteristics (FTIR and NMR-H-C) which corroborate proposed structure are reported. The reaction of phenolic substrates with Benzal-Br3 in dichloromethane-methanol mixture during 1-3h at ambient temperature allows to obtain the corresponding bromoderivatives (>75%). This procedure allows, without special conditions, to synthesize a series of
bromosubstituted phenols on dependence of the brominating agent's molar quantity (1:1; 2:1; 3:1) vs. phenolic substrates used.

Traditionally, humanity has relied on Nature for treating several diseases. In recent years essential oils (EOs) became an important source of bioactive compounds. Eugenol (4-ally-2-methoxyphenol) is a phenolic compound from the class of phenylpropanoids that can be found in numerous EOs from plants, such as Syzygium aromaticum. Eugenol has commercial relevance in the food and cosmetics industries, and also had shown biological properties such as anti-inflammatory, anti-oxidant, anti-tumorigenic, anti-microbial and cytotoxic activity. The interest in this molecule has been increasing also because of its structure, which is interesting for a starting molecule.

In light of the biological properties of eugenol, in this study the cytotoxic activity of various β-amino alcohols and β-alkoxy-alcohols obtained from eugenol was studied in AGS (gastric cancer) and A549 (lung cancer) cell lines. The results show that some structural modifications resulted in enhanced cytotoxic activity towards cancer cells. In addition, the occurrence of a process of programmed cell death, specifically apoptosis, was also studied. Considering the results, some structure/activity relationships can be drawn, which may guide future structural improvements in this lead molecule.

Heterocyclic compounds are abundant in natural products, bioactive compounds and play a huge role in the present repertoire of medicinal chemists due to their potential capability to modulate physicochemical properties. As a result, chemists have focused their efforts on the functionalization of heterocycles. Nitrogen-containing fused heterocyclic compounds are important organic molecules. They're found in a variety of natural products, medicinal compounds, and functional materials as structural fragments. The imidazo[1,2-a]pyrimidine skeleton is one of them, and it's linked to the pharmacological activity of related drugs. Anticancer activity medicines, anxiolytic drugs, and anti-inflammatory activity pharmaceuticals all have this structural pattern. Many of them have biological properties, such as antifungal, antimicrobial, antiviral, and anxiolytic properties, which are used in medications like divaplon and fasiplon.

The invention of a new approach to manufacture 2- arylsubstituted imidazo[1,2-a]pyrimidines efficiently piqued our interest, given the powerful bioactivities of molecules with an imidazopyrimidine core. As a result, appropriate methods for manufacturing such molecules remain appealing. In this context, we'd like to present a feasible green chemistry approach for the synthesis of 2-phenyl-imidazo [1,2-a] pyrimidines.

Metronidazole is an antimicrobial, antibacterial and antiprotozoal drug that is applied to treat many infections. However, it has been considered as a pollutant in water bodies. In this study, Co-Zr layered double hydrodxide (LDH) was synthesized using cobalt and zirconium metal salts by mechanochemical method. Layered double hydroxides are generally described as [M²⁺_1-xM³⁺_x(OH)₂]^x+(A^n-)_x/n·mH₂O, where M²⁺ and M³⁺ are divalent and trivalent metal cations, respectively. Here, we used divalent and tetravalent metal cations and A is an n-valent interlayer guest anion. The LDH was characterized by XRD, FE-SEM and IR methods, and then was used to adsorb metronidazole in aqueous solution. We have optimized the pH to obtain the maximum adsorption capacity which was determined by UV-VIS spectroscopy. The results showed that this adsorbent had better performance than previous studies.

Imidazo[2,1-b][1,3]thiazine scaffold is the attractive matrix for the design of small molecules with a wide activity spectrum. Therefore, it seemed to be interesting to work out the straightforward and convenient protocol for the synthesis of new hybrid molecules containing diversified imidazo[2,1-b][1,3]thiazine scaffolds linked with potential pharmacophore – pyridine ring and evaluate their drug-like and anti-inflammatory properties. The proposed synthetic approach is based on the utilization of structure-modified imidazolinthiones as starting building block for the formation of imidazo[2,1-b][1,3]thiazine core. The interaction of the last ones in the soft conditions with epichlorohydrin lead to the key 3-hydroxy-imidazo[2,1-b][1,3]thiazines, which were easily transformed to the target (2-pyridinyloxy)substituted imidazo[2,1-b][1,3]thiazines with satisfied yields (53-74%) due to selective nucleophilic substitution by different chloropyridines at room temperature using dry DMF and in the presence of NaH. The structure of compounds was studied and confirmed using ¹H, ¹³C NMR spectroscopy and LC-MS spectrometry. The drug-likeness properties of the synthesized derivatives were determined based on Lipinski and Veber rules and evaluated in silico using the SwisAdme. Almost all tested compounds comply with Lipinski’s rules of five and Veber’s rules, with some exceptions for Mlog P parameter. The anti-inflammatory activity of all synthesized (2-pyridinyloxy)substituted imidazo[2,1-b][1,3]thiazines was studied in vivo using the carrageenin model of edema of hind paws of albino rats. The compounds possess different levels of anti-inflammatory activity (inhibition index was in the range of 3.7 to 39.1 %). The “structure – anti-inflammatory activity” correlation was revealed for the next structure optimization and focused synthesis of imidazo[2,1-b][1,3]thiazine with anti-inflammatory activity.

The aim of this work is to develop a one-stage catalytic method for the preparation of alkyl esters of benzoic acid by the direct reaction of benzene and its derivatives with alcohols and halogenmethanes. We found that the reaction of benzene, phenol, and anisole with CCl4 and alcohol under the action of the [Fe] –acetylacetone catalyst leads to the formation of practically important esters of alkyl benzoates, as well as salicylic and p-hydroxybenzoic acids. The advantage of the developed method for the synthesis of esters of benzoic acid is the availability and low cost of the main starting reagents - benzene, phenol, anisole, CCl4, alcohols and iron, cost reduction and simplification of technology, moderate reaction time (6 h), relatively low temperature, one-step process, possibility the use of this reaction in an industrial environment (scaling).

Three-component couplings of ketones, alkynes, and amines (KA2 reaction) are the most efficient method of forming tetrasubstituted propargylamine building blocks for rapid access to biologically active targets. Typically, the reaction is carried out at temperatures above 100 °C (or under microwave irradiation conditions) in the presence of copper catalysts in toluene or without solvent. The use of AuBr3 instead of copper salts allows the reaction temperature to be reduced to 60 °C. We have discovered for the first time that the CuI - TIBAL catalytic system (20 mol. %) makes it possible to carry out similar reactions in dichloromethane or dichloroethane in quantitative yield even at room temperature. Alkyl- and aryl-substituted terminal acetylenes (including diacetylenes), a number of secondary amines (piperidine, pyrrolidine, dibutylamine) and a number of ketones (cyclohexanone, cyclopentanone, acetone, 2-octanone, 3-nonanone) were involved in KA2 reaction. A solvent is an important factor in the reaction. The use of toluene and hexane leads to a negligible yield of tetrasubstituted propargylamines at room temperature. Thus, we found an activating effect of the TIBAL additive and dichloromethane on the KA2 reaction.