A. N. Borisevich

Cycloacylation of N-Phenyl-3-oxobutanethioamide with 3-Aryl-2-propenoyl Chlorides

Reactions of N-phenyl-3-oxobutanethioamide with 3-aryl-2-propenoyl chlorides in acetone in the presence of potassium carbonate give rise to 4-aryl-5-acetyl-1-phenyl-6-thioxopiperidin-2-ones, 2-aryl-5-acetyl-6-phenylamino-2,3-dihydro-4H-thiopyran-4-ones, and 6-aryl-2-acetonylidene-3-phenyl-5,6-dihydro-4H-1,3-thiazin-4-ones whose structure was proved both by spectral methods and chemical transformations.

Reaction of 3-oxo-N-phenylbutanethioamide with 5-amino-1H-1,2,4-triazoles

Reactions of 3-oxo-N-phenylbutanethioamide with 3-substituted 5-amino-1H-1,2,4-triazoles in acetic acid led to the formation of 5-methyl-7,8-dihydro[1,2,4]triazolo[1,5-a]pyrimidine-7-thiones, 7-methyl-5,8-dihydrol[1,2,4]triazolo[1,5-a]pyrimidine-5-thiones and 7-methyl-5-phenylamino[1,2,4]triazolo[1,5-a]pyrimidines. The structure of the products was proved by the 1H and 13C NMR spectra, X-ray diffraction data, and chemical transformations.

General trends in reaction of N-aryl-3-oxobutanethioamides with 2-aminoazoles(azines)

Reaction products obtained from N-aryl-3-oxobutanethioamides and 2-aminoazoles(azines) are derivatives of (arylamino)pyrimidines and pyrimidinethiones. The ratio of the products depends on the basicity of 1,3-binucleophiles, acidity of the medium, and the character of substituents in the phenyl ring of initial thioamides.

Oxalylation of the 3-oxo-N-phenyl-3-R-propanethioamides

Oxalylation of 3-oxo-N-phenyl-3-R-propanethioamides in aprotic solvents in the temperature range from −40°C to +20°C results in 4-acyl-5-phenylamino-2,3-dihydrothiophene-2,3-diones and 2-(2-oxo-2-R-ethylidene)-3-phenyl-1,3-thiazolidine-4,5-diones, while in the presence of potassium carbonate, potassium 4-acyl-2,3-dioxo-1-phenyl-2,3-dihydro-1H-pyrrole-5-thiolates are formed.

Reaction of N-aryl-3-oxobutanethioamides with bis(guanidinium) carbonate

Reactions of N-aryl-3-oxobutanethioamides with bis(guanidinium) carbonate lead to the formation of N-aryl-3-guanidinobut-2-enethioamides, 4-arylamino-6-methylpyrimidin-2-amines, guanidinium acetate, and arylamines, depending on the temperature conditions.

Reaction of N-aryl-3-oxobutanethioamides with 2-amino-1,3-thiazole and 2-amino-1,3-benzothiazole

N-Aryl-3-oxobutanethioamides react with 2-amino-1,3-thiazole (2-amino-1,3-benzothiazole) in acetic acid to give mixtures of 7-methyl-5H-[1,3]thiazolo[3,2-a]pyrimidine-5-thione (2-methyl-4H-pyrimido-[2,1-b][1,3]benzothiazole-4-thione) and 5-arylimino-7-methyl-5H-[1,3]thiazolo[3,2-a]pyrimidines (4-arylimino-2-methyl-4H-pyrimido[2,1-b][1,3]benzothiazoles), whose ratio depends on the nature of the aryl substituent in the initial butanethioamide.

Synthesis of 3-(6-R-Benzothiazol-2-yl)-4-methyl-1,2,5-oxadiazoles

The nitrosation of N-aryl-3-oxobutanethioamides afforded 1-(6-R-benzothiasol-2-yl)-1-hydroxyimino-2-propanones that at oximation with hydroxylamine were converted into 1-(6-R-benzothiazol-2-yl)-1,2-dihydroxyiminopropanes. The latter were dehydrated by heating with succinic anhydride at 140°C yielding therewith 3-(6-R-benzothiazol-2-yl)-4-methyl-1,2,5-oxadiazoles.

pH-dependent isomerism of (Iso)thioureidomethylenebisphosphonates

Isomerism of thioureas bearing a methylenebisphosphonic group was studied. It was shown that a change in the ionization degree of the bisphosphonic group affects the strength of intramolecular hydrogen bonds and Z/E ratio in the solution.

Cycloacylation of 3-oxo-3-R1-N-R2-propanethioamides by 3-aryl-2-propenoyl chlorides

The products of cyclocondensation of 3-oxo-3-R1-N-R2-propanethioamides with 3-aryl-2-propenoyl chlorides in acetone in the presence of potassium carbonate are 5-acyl-1-aryl(alkyl)-4-aryl-6-thioxopiperidin-2-ones, 5-acyl-2-aryl-6-aryl(alkyl)amino-2,3-dihydro-4H-thiopyran-4-ones, and 2-acetonylidene-3,6-diaryl-5,6-dihydro-4H-1,3-thiazin-4-ones, the structure of which is proven by both spectral methods and chemical conversions.

Synthesis and Heterocyclization of 3-Arylaminothiocrotonanilides

Reactions of acetylthioacetanilide with arylamines in acetic acid in the presence of sodium acetate give 3-arylaminothiocrotonanilides in good yields. When treated with ω-bromoacetophenone in acetone, these products are converted to substituted 4-hydroxy-Δ2-thiazolinium bromides, one of which was dehydrated to obtain the corresponding thiazolium bromide. The structure of the heterocyclization products was confirmed by single crystal X-ray diffraction and NMR study of 2-acetonylidene-3,4-diphenyl-2,3-dihydrothiazole formed by dehydration of the corresponding Δ2-thiazolinium salt with simultaneous hydrolysis.