The reactions of chloroethynylphosphonates with 4-substituted thiosemicarbazides leads to the predominant formation of dialkyl esters of 5-substituted (1,3,4-thiadiazol-2-yl)methylphosphonic acids with an admixture (up to 31%) of dialkyl [3-amino-2-(alkylimino)-2,3-dihydro-1,3-thiazol-4-yl)phosphonates as a minor product.

Glycosylation of 4-(4-hydroxyphenyl)-1,2,3-thia(selena)diazoles with 1-α-bromo-2,3,4,6-tetra- O -acetyl-D-glucopyranose, 1-α-bromo-2,3,4,6-tetra- O -acetyl-D-galactopyranose, and 1-α-bromo-2,3,5-tri- O -acetyl-D-xylopyranose under the conditions of interphase catalysis has afforded the corresponding acetylated glycosides. An alternative pathway of selenadiasole glycosides synthesis from semicarbazones of 1-β- O -(4-acetylphenyl)-2,3,4,6-tetra- O -acetyl-D-glucopyranose, -2,3,4,6-tetra- O -acetyl-D-galactopyranose, and -2,3,5-tri- O -acetyl-D-xylopyranose via oxidation with selenium dioxide has been elaborated.

The coupling of bis(xylylisocyanide) complex of Pd(II) with 1,2,4-thiadiazole-5-amines leads to the formation of an equilibrium mixture of the binuclear complexes. In each of the studied cases, one of the formed complexes is the kinetic product, and the other one is the thermodynamic product. The complexes which are thermodynamic products have been isolated in the pure form and characterized by means of high-resolution mass spectrometry, IR and NMR spectroscopy, and X-ray diffraction analysis. NMR study of the regioisomerization in a solution has revealed that the relative stability of the thermodynamic products in comparison with the kinetic ones is higher than for the corresponding regioisomers containing 1,3-thiazole or 1,3,4- thiadiazole fragment.

Methods of synthesis of 4-functionalyzed (5-trifluoromethylfur-2-yl)methanephosphonates and (5-methyl-2-trifluoromethylfur-3-yl)methanephosphonate are developed. Their formylation with ethyl formate in the presence of sodium foil is studied. Spectral characteristics of tautomers of obtained derivatives of phosphonoacetic aldehyde are evaluated. It is shown that interaction of obtained formyl derivatives with ethoxycarbonylmethylenetriphenylphosphorane regardless of the structure of the furan fragment leads to 4-furylsubstituted alkyl 4-(diethoxyphosphoryl)but-3-enoate, the abnormal product of Wittig reaction.

A number of thioglycosides derived from benzoylated glucopyranose and nitrogen-containing heterocyclic thiols have been synthesized in up to 98% yield, and benzoyl protecting groups have been removed from the glycoside with a 3-phenyl-4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl fragment.

The reaction of chloroethynylphosphonates with N-substituted benzimidazole-2-thiones proceeded chemo- and regioselectively with the formation of cyclic zwitterions, namely alkyl (9H-benzo[4,5]imidazo[2,1-b]-thiazol-3-yl-4-ium)phosphonates. Chemo- and regioselective reaction of N-unsubstituted benzimidazole-2-thione with chloroethynylphosphonates led to the production of linear Z-1,2-bis(1H-benzimidazol-2-ylsulfanyl)-ethenylphosphonates.

Получена серия тиогликозидов бензоилированной глюкопиранозы с фрагментами азотсодержащих гетероциклов с выходами до 98% и проведено снятие бензоильных групп у гликозида с электроноакцепторной фенильной группой.

By adding diethyl hydrogen phosphite to 5-trifluoromethyl-2-furaldehyde (5-trifluoromethylfur-2-yl)(diethoxyphosphoryl)methanol was synthesized. It was oxidized with DMSO-acetic anhydride mixture to diethyl 5-trifluoromethyl-2-furoyl phosphonate. The reaction of the latter with ethoxymethylenetriphenylphosphorane gives ethyl (2E)-3-(diethoxyphosphoryl)-3-(5-trifluoromethylfur-2-yl)propenoate. Analogous reaction of (diethoxyphosphoryl)(5-trifluoromethylfur-2-yl)acetic aldehyde yields ethyl (4E)-4-(diethoxyphosphoryl)-4-(5-trifluoromethylfur-2-yl)-but-3-enoate. The addition of nitromethane to these esters of unsaturated acids in the presence of potassium fluoride gives a mixture of diastereomers of phosphorylated esters of 2-nitromethyl-3-(5-trifluoromethylfur-2-yl)propanoic and 3-nitromethyl-4-(5-trifluoromethylfur-2-yl)butanoic acids respectively. By the reduction of ethyl nitropropanoate with zinc and formic acid in dioxane ethyl 2-aminomethyl-3-(diethoxyphosphoryl)-3-(5-trifluoromethylfur-2-yl)propanoate was prepared in a low yield. It may be considered as the derivative of β-alanine containing additional pharmacophore fragments.

Methods of synthesis of trifluoromethylfuryl derivatives of phosphonocarboxylic acids are studied. By addition of diethyl hydrogen phosphite to alkyl 3-(5-trifluoromethylfur-2-yl)acrylate under the conditions of the Pudovik reaction the corresponding derivative of 3-phosphonopropionic acid was prepared. Diethyl (5-trifluoromethylfur-2-yl)methanephosphonate in presence of potassium tert-butylate reacts with ethyl acrylate to form trifluoromethylfuryl derivative of 4-phosphonobutyric or 4-phosphonopimelic acid depending on the reaction conditions. In the products of reaction of the alkyl 3-(5-trifluoromethylfur-2-yl)-3-(diethoxyphosphoryl) propionate with ethyl acrylate in the presence of potassium tert-butylate formation of trifluoromethylfuryl derivative of the 3-phosphonoadipic acid is detected. 3-(5-Trifluoromethylfur-2-yl)-3-(diethoxyphosphoryl) propionic acid and its acid chloride are synthesized. The latter compound is used for acylation of glycine to form the corresponding N-acyl derivative. It is suggested that such compounds may be transported in the cell using usual channels of transportation of the amino acids and short peptides.

The structure of the condensation products of 2-hydroxybenzohydrazide, 2-aminobenzohydrazide, and N-methyl-N-(2-aminobenzo) hydrazide with a series of aldoses (L-arabinose, D-ribose, L- rhamnose, D-galactose, D-glucose, and D-mannose) was studied by 1H- an...

Regioselectivity of the methanolysis of lower polychlorinated biphenyls with sodium methoxide in a mixture of methanol and DMSO at 100–130°С was studied. It was found that 2,4,4'-tricholobiphenyl is much more reactive than 2,4-dichlorobiphenyl. This results in different mechanisms of substitution. 2,4-Dichlorobiphenyl reacts with sodium methoxide by the elimination–addition mechanism to form four monosubstitution products in comparable quantities. 2,4,4'-Trichlorobiphenyl reacts with the methodixe ion by the classical SNAr mechanism, with preferential substitution of the 2-chlorine atom.

Optically pure (2 S ,4 S )-2-alkyl-6-oxo-3-(phenylcarbamothioyl)hexahydropyrimidine-4-carboxylic acids have been synthesized from natural L-asparagine, commercially available aldehydes, and phenyl isothiocyanate. The product structure was confirmed by 1 H and 13 C NMR data.

By the interaction of 2-bromomethyl-5-trifluoromethyfuran with triethyl phosphite under the Arbuzov reaction conditions diethyl (5-trifluoromethylfur-2-yl)methanephosphonate was prepared. Due to deactivation of the furan ring this substance does not enter chloromethylation even at 70°C. Because of CH-acidity of the diethoxyphosphorylmethyl fragment diethyl (5-trifluoromethylfur-2-yl)methanephosphonate in the presence of sodium foil enters the Claisen reaction with ethyl formate and diethyl oxalate. Respective derivatives of furylacetaldehyde and furylpyruvic acid and their sodium salts were isolated and characterized. Reactions of the compounds obtained with methyl iodide and diethyl chlorophosphate were studied. It was shown that trifluoromethyl derivative of phosphorylated furylacetaldehyde forms stable enol ethers and esters. The furylpyruvic acid derivative is alkylated with methyl iodide at the carbon atom adjacent to phosphorus and the compound formed undergoes cleavage to 1-(5-trifluoromethylfur-2-yl)ethanephosphonate.

AbstractAzo‐coupling of diazonium salts (II) with chloroacetoacetate, followed by intramolecular cyclization of hydrazones (III) in the presence of ethyl chloroformate (V) under basic conditions yields a novel family of pyrazoles (VI), instead of the expected hydrazone derivatives.

Two-step synthesis of N-aryl 4-[(ethoxycarbonyl) oxy]-1H-pyrazole-3-carboxylates is achieved starting from the commercially available ethyl 4-chloroacetoacetate and aromatic amines. Azo coupling followed by cyclization with ethyl chloroformate-DMAP pair resulted in the formation of new 4-oxy-1H-pyrazole derivatives in high yields.

Oxidation of 3-methyl-2-sulfanylquinazolin-4(3H)-one with chlorine dioxide under different conditions gave 2,2′-disulfanediylbis[3-methylquinazolin-4(3H)-one], 3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonic acid, 3-methylquinazoline-2,4(1H,3H)-dione, 6-chloro-3-methylquinazoline-2,4(1H,3H)-dione, and N,N-diethyl-3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonamide.

AbstractSulfides (I) are highly chemoselectively oxidized to their corresponding sulfoxides (II) with chlorine dioxide.

3-Benzylsulfanyl-4,5-diphenyl-4 H -1,2,4-triazole, 5-methylsulfanyl-1-phenyl-1 H -tetrazole, 2-methylsulfanyl-1 H -benzimidazole, 2-benzylsulfanyl-1 H -benzimidazole, and 1-butylsulfanyl-4-nitrobenzene were oxidized to the corresponding sulfoxides with chlorine dioxide using different modes of oxidant supply. The oxidation process was characterized by high chemoselectivity.