New possibilities of the Mannich reaction in the synthesis of N-, S,N-, and Se,N-heterocycles

The Reactions of N,N'-Diphenyldithiomalondiamide with Arylmethylidene Meldrum's Acids

The Michael addition reaction between dithiomalondianilide (N,N'-diphenyldithiomalondiamide) and arylmethylidene Meldrum's acids, accompanied by subsequent heterocyclization, was investigated along with factors affecting the mixture composition of the obtained products. The plausible mechanism includes the formation of stable Michael adducts which, under the studied conditions, undergo further transformations to yield corresponding N-methylmorpholinium 4-aryl-6-oxo-3-(N-phenylthio-carbamoyl)-1,4,5,6-tetrahydropyridin-2-thiolates and their oxidation derivatives, 4,5-dihydro-3H-[1,2]dithiolo[3,4-b]pyridin-6(7H)-ones. The structure of one such product, N-methylmorpholinium 2,2-dimethyl-5-(1-(2-nitrophenyl)-3-(phenylamino)-2-(N-phenylthiocarbamoyl)-3-thioxopropyl)-4-oxo-4H-1,3-dioxin-6-olate, was confirmed via X-ray crystallography.

Synthesis and Aminomethylation of 2-Amino-4-(2-chlorophenyl)-6-(dicyanomethyl)-1,4-dihydropyridine-3,5-dicarbonitrile N-Methylmorpholinium Salt

Sequential reaction of 2-chlorobenzaldehyde, cyanothioacetamide, and malononitrile dimer in the presence of an excess of N-methylmorpholine resulted in the formation of N-methylmorphlinium salt of 2-amino-4-(2-chlorophenyl)-6-(dicyanomethyl)-1,4-dihydropyridine-3,5-dicarbonitrile. The resulting salt reacts under Mannich conditions with primary amines and an excess of formaldehyde to form substituted 2-alkylamino-4-(dicyanomethylene)-3,7-diazabicyclo[3.3.1]non-2-ene-1,5-dicarbonitriles. Structure of the key compound was confirmed by single crystal X-ray diffraction analysis.

Reactions of Malononitrile Dimer with Isothiocyanates

Abstract

The reaction of 2-amino-1,1,3-tricyanopropene (malononitrile dimer) with isothiocyanates leads to 1-substituted 4,6-diamino-2-thioxo-1,2-dihydropyridine-3,5-dicarbonitriles or 4,6-diamino-2-(phenylimino)-2H-thiopyran-3,5-dicarbonitrile, depending on the conditions. Quantum-chemical modeling of the IR spectra and reaction routes for the synthesized compounds was carried out. In silico predictive analysis of potential protein targets, compliance with bioavailability criteria, and ADMET parameters was performed.

Access to molecular complexity. Multicomponent reactions involving five or more components

The evaluation of the significance of a chemical transformation addresses many factors, including such important characteristics as the number of chemical bonds formed in one step, the reaction time, labour intensity, the cost of reactants and catalysts and so on. The amount of waste produced in the reaction has also gained increasing importance in recent years. Multicomponent reactions (MCRs) occupy a special place as a synthetic tool in modern organic chemistry. These reactions allow the synthesis of target products with complex structures, minimizing labour costs. This review summarizes the literature on multicomponent reactions involving five or more components. The data in the review are classified according to the number of reactants participating in the reaction and the types of reactions. It is worth noting that in some cases, these transformations can be a part of a domino process, making this classification difficult, if not impossible. The structural diversity of the reaction products greatly increases with increasing number of components involved in the MCR, which becomes virtually unlimited when using combinations of MCRs. This review highlights the main trends of past decades in the field of MCRs. The last two decades have witnessed an explosive growth in the number of publications in this area of chemistry.

The bibliography includes 309 references.

Peculiarities of Pharmacological Activity of Tetrahydropyridone and Hexahydroquinoline Derivatives in Experiment

Introduction: Due to widespread inflammatory processes, often accompanied by pain and fever syndromes, NSAIDs are now the most prescribed drug group in the world. NSAIDs are characterized by taking a leading position in the number and severity of adverse actions. In recent decades, the efforts of scientists have been aimed at seaching for adequate ways to increase the safety profile of NSAIDs.

Materials and methods: In a series of experiments, the main objects of research were derivatives of α-cyanothioacetamide – new tetrahydropyridones under laboratory codes TD 0364, TD 0353, TD 0351, CV 036, as well as hexahydroquinolines CV 125 and OCO 5184. One promising area for searching for effective and safe pharmacological agents is some derivatives of α-cyanothioacetamide (CAS Number: 7357-70-2). The trigeminal orofacial pain test and the thermal tail immersion test were used to assess the analgesic effect. Determination of antipyretic activity was carried out on the yeast-fever model. To study an anti-inflammatory activity, the method of subacute non-infectious parotitis was used.

Results and discussion: The results of the experiment made it possible to find among the new samples of tetrahydropyridones and hexahydroquinolines the compounds with analgesic, anti-inflammatory and antipyretic activities, which, in terms of these types of activities in dynamics, surpass the reference (paracetamol, diclofenac sodium, and ketorolac). It is important that these compounds have low acute toxicity.

Conclusion: The consequence of the above is the necessity of further preclinical and clinical studies of samples of α-cyanothioacetamide derivatives in order to create new promising highly effective and safe drugs with analgesic, anti-inflammatory and antipyretic activities.