Vol. 16 No. 2(62) (2018)
Published:
2018-06-08
Original Researches
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The synthesis and transformation of 4-phosphorylated derivatives of 1,3-azoles
The review systematizes the literary data on the methods of the synthesis of 4-phosphorylated 1,3-azoles (oxazoles, thiazoles, selenazoles, imidazoles), as well as their chemical and biological properties. For the synthesis of 4-phosphorylated imidazole derivatives metallic derivatives of imidazole and phosphorus halides, electronically enriched imidazoles and phosphorus halides in pyridine in the presence of triethylamine or a cross-coupling of halogenimidazoles and dialkyl phosphites in the presence of a palladium catalyst are generally used. For the synthesis of 4-phosphorylated 1,3-azoles the acyclic phosphorus-containing reagents have been widely used, in particular 1-phosphorylated derivatives of 2-chloro- and 2,2-dichloroethenylamides, aminomethylphosphonates and their triphenylphosphonium analogs, β-ketopphosphonates, phosphorylated α-halogenocarbonyl compounds. The chemical properties of phosphorylated azoles are represented by phosphorus residue modification reactions, modification of other substituents and the azole ring, as well as reactions involving the disclosure of the azole ring. The latter are the most interesting since they provide an opportunity to conduct recyclization reactions, as well as synthesize an important class of organic compounds – phosphorylated peptidomimetics. Due to the systematic study of derivatives of 1,3-azoles over the last 30 years it has been shown that at least one fragment of the 1,3-azole ring is a part of a wide range of simple and complex natural molecules and synthetic drugs. Synthetic 4-phosphorylated derivatives of 1,3-azoles are characterized by insectoacaricidal, anti-blastic, sugar-lowering, anti-exudative, antihypertensive, neurodegenerative and other types of activity.
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The synthesis and structural functionalization of 6-substituted 2,3-dihydroimidazo[2,1-b] [1,3]thiazol-5-ones
Aim. To extend the synthetic limits of the reaction of the electrophilic intramolecular cyclization (EIC) on the examples of 5,5-disubstituted and 5-yliden substituted 3-allyl-2-thiohydantoins and the directed structural modification of 2-halogenomethyl-2,3-dihydroimidazo[2,1-b][1,3]thiazole-5-ones obtained.
Results and discussion. It has been found that the cyclization of 5,5-disubstituted and 5-yliden substituted 3-allyl-2-thiohydantoins under the effect of polyphosphoric acid (PPA), bromine and iodine is an effective method for the synthesis of new 2,3-dihydroimidazo[2,1-b][1,3]thiazole-5-ones. The reaction of the nucleophilic substitution of their 2-halogenomethyl representatives was used to obtain a number of sulfur-containing derivatives and azides. The latter were tested in the reaction of [3+2]-cycloaddition with N-phenylmaleinimide and propargyl alcohol.
Experimental part. A series of 2-substituted 2,3-dihydroimidazo[2,1-b][1,3]thiazole-5-ones was synthesized by the reaction of 5,5-disubstituted and 5-yliden substituted 3-allyl-2-thiohydantoins with PPA and halogens with the yields of 66-96 %. A directed modification of the halogenomethyl group of imidazotiazolones produced a series of sulfur-containing derivatives and azides with the yields of 63-93 %. The azides synthesized were used in the [3+2]-cycloaddition reaction with N-phenylmaleinimide and propargyl alcohol leading to 1,2,3-triazoloderivatives with the yields of 51-85 %; their structure was confirmed by the complex spectral analysis.
Conclusions. A convenient method for the synthesis of 2-halogenomethyl-substituted imidazo[2,1-b][1,3] thiazoles, which are effective reagents for the directed structural modification by sulfur- and nitrogen-containing functional groups, has been developed. -
Molecular docking and assessment of thiacalix[4]arene and sulfonylcalix[4]arene as a platform for designing glutathione S-transferase inhibitors
It is known that overexpression of isozymes of glutathione S-transferase family is one of the causes for the resistance of cancer cells to the action of drugs. Therefore, inhibitors of these enzymes can be considered as potential drugs.
Aim. To assess in silico calix[4]arene, thiacalix[4]arene, and sulfonyl alkyl[4]arene as a molecular platform for designing inhibitors of glutathione S-transferase.
Results and discussion. Docking models of complexes of glutathione S-transferase with α-hydroxymethylphosphonate derivatives of calix[4]arene, thiacalix[4]arene, and sulfonylcalix[4]arene were calculated and analyzed. The binding models obtained by AutoDock 4.2 program were assessed by the molecular dynamics simulations. It has been shown that sulfonyl groups of the sulfonylcalix[4]arene macrocycle can be involved in additional stabilization of the enzyme-inhibitor complex. In addition, the affinity of the inhibitors to the enzyme depends on the stereoisomeric α-hydroxymethylphosphonate residues located at the upper rim of the macrocycle.
Experimental part. Molecular docking of macrocyclic compounds to the active site region of glutathione S-transferase was performed using AutoDock 4.2 and AutoDock Vina. Molecular dynamics was modeled using NAMD 2.10 program.
Conclusions. It has been determined that sulfonylcalix[4]arene can be a promising molecular platform for designing inhibitors of glutathione S-transferase. -
Development of quality control methods for the substance 4-benzyl-1-{4-[4-(4-methoxyphenyl)- piperazin-1-yl]-4-oxobutyl}[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one
Aim. To develop the project of quality control methods for the leader compound among derivatives of [1,2,4]triazolo[4,3-a]quinazoline-5(4H)-ones, namely 4-benzyl-1-{4-[4-(4-methoxyphenyl)-piperazin-1-yl]-4-oxobutyl}-[1,2,4]triazolo[4,3-a]quinazolin-(4H)-one as a promising antimalarial agent for further in-depth studies.
Experimental part. Taking into account the requirements of the general monograph “Substances for pharmaceutical use” it has been proposed to include the following indicators to the project of quality control methods: description, solubility, identification (using infrared and ultraviolet spectroscopy), related impurities (liquid chromatography method), the loss on drying, the residue on ignition, residual organic solvents, microbiological purity, assay by potentiometric titration with chloric acid in acetic acid.
Conclusions. The methods of quality control of a leader compound – 4-benzyl-1-{4-[4-(4-methoxyphenyl)- piperazin-1-yl]-4-oxobutyl}[1,2,4]-triazolo[4,3-a]quinazolin-(4H)-one have been developed.
