Synthesis and reactions of 3-aminothiazolidine-2-thion-4-one derivatives. 2. 3-[R-(Alkylthio)methylene]aminothiazolidine-2-thion-4-ones

3-[R-(Alkylthio)methylene]aminothiazolidine-2-thion-4-ones were obtained by the reaction of 3-aminorhodanine with thioimino ester hydriodides.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 199–201, February, 1981.     

Synthesis and reactions of 3-aminothiazolidine-2-thion-4-one derivatives. 3. Reaction of 3-[N-(α-methylthio)ethylidene] aminothiazolidine-2-thion-4-one with amines

It is shown that recyclization leading to the formation of 1,3,4-thiadiazole derivatives occurs in the reaction of 3-[N-(-methylthio)ethylidene]aminothiazolidine-2-thion-4-one with amines. The structures of the compounds obtained were established by spectral methods and were confirmed by alternative synthesis.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 339–342, March, 1981.     

Synthesis and reactions of 3-aminothiazolidine-2-thion-4-one derivatives. 4. Thiazolo[3,4-b][1,2,4]treiazole derivatives

It is shown that derivatives of a new heterocyclic system, viz., thiazolo[3,4-b][1,2,4]triazole, the structure of which was established by means of their IR and PMR spectra, are formed in the reaction of 5-substituted 3-aminorhodanines with imidoyl chlorides.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 331–333, March, 1982.     

Ab initio study of 2,4-substituted azolidines. II. Amino-imino tautomerism of 2-aminothiazolidine-4-one and 4-aminothiazolidine-2-one in water solution

The relative stabilities of the tautomers of 2-aminothiazolidine-4-one and 4-aminothiazolidine-2-one were calculated at the MP2/6-31+G(d,p) level by considering their mono- and trihydrated complexes. Single-point calculations at the MP4/6-31+G(d,p)//MP2/6-31+G(d,p) level of theory were performed to obtain more accurate energies. The values of proton transfer barriers in the isolated, mono- and trihydrated tautomers of 2-aminothiazolidine-4-one (2AT) and 4-aminothiazolidine-2-one (4AT) were calculated for two different mechanisms of tautomerisation. In the absence of water, the process of proton transfer should not occur. Addition of water molecules decreases the barrier making the process faster, as the participation of two water molecules in a proton transfer reaction is more favorable than the participation of only one water molecule. To estimate the effect of the medium (water) on the relative stabilities of the tautomers of the studied compounds we applied the polarizable continuum model (PCM). (13)C NMR chemical shieldings were calculated using the GIAO approach at MP2/6-31+G(d,p) optimized geometries. HF and the DFT B3LYP functional with 6-31+G(d,p) basis set were employed. The quantum chemical results for the chemical shifts in gas phase and in polar solvents (water and DMSO) were compared with experimental data. TD DFT B3LYP/aug-cc-pVTZ calculations were performed to predict the absorption maxima of tautomers A and B of 2AT and 4AT.     

Synthesis of novel derivatives of 2-(azolylimino)thiazoline

Successive alkylation of 5-(3-phenylthioureido)-3H-imidazole-4-carboxamides with alkyl halides and chloroacetone gave (N-oxopropylimidazolyl)isothioureas, which were easily converted into derivatives of purine and imidazopyrazinone. In the case of ethyl 5-(3-phenylthioureido)-3H-imidazole-4-carboxylate, primary alkylation occurs at the N atom of the imidazole ring. Reactions of 5-(3-phenylthioureido)-3H-imidazole-4-carboxamides with haloketones afforded a number of 4-hydroxy-2-imidazolyliminothiazolidines and 2-imidazolylimino-Δ⁴-thiazolines.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2196–2204, October, 2004.     

Synthesis of 2-thioxo-1,3-thiazolidin-4-one derivatives

A series of new 2-thioxo-1,3-thiazolidin-4-one derivatives containing arylidene, arylazo, and aminomethylene fragments in position 5 of the rhodanine cycle was synthesized. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1564–1569, August, 2007.     

Synthesis and reactions of 3-aminothiazolidine-2-thion-4-one derivatives. 5. Polymethine dyes of the thiazolo[3,4-b][1,2,4]triazole series

It is shown that the reaction of thiazolo[3,4-b][1,2,4]triazole-5-thiones with alkylating agents gives 5-methylthiothiazolotriazolium salts, which react with the appropriate intermediates to give polymethine dyes.See [1] for Communication 4.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 480–483, April, 1982.     

3-(2,5-Dioxopyrrolidin-1-yl), 3-(2,6-dioxopiperidin-1-yl), and 3-(1,3-dioxoisoindolin-2-yl)rhodanines. a novel type of rhodanine derivatives

3-Aminorhodanine 2 was reacted with cyclic anhydrides yielding 3-(2,5-dioxopyrrolidin-1-yl), 3-(2,6-dioxopiperidin-1-yl), and 3-(1,3-dioxoisoindolin-2-yl)rhodanine 6-8 , which in turn were condensated in 5 position with several aldehydes yielding the new rhodanine derivatives 9-11 .     

3-Benzamido, ureido and thioureidoimidazo[1,2-a]pyridine derivatives as potential antiviral agents.

This work reports the synthesis and the antiviral activities of 3-benzamido, 3-phenylureido and 3-phenylthioureido derivatives in the imidazo[1,2-a]pyridine series. The structure was proven by NMR spectroscopy. The synthesized compounds were evaluated against a large number of viruses. The 3-phenylthioureido derivative 7 showed moderate activity against human cytomegalovirus (HCMV) in vitro. The crystallographic data for 8 are also reported and explain the absence of activity against human immunodeficiency virus (HIV).     

3-(Thiazolidin-3-yl)rhodanines. A novel class of rhodanine derivatives

α-Bromoacetylaminorhodanines 1 were reacted with NH₄SCN yielding 3-(thiazolidin-3-yl)rhodanines 4 , a novel type of rhodanine derivatives bearing a uncommon N-N ring-connection.     

Lactam and acid amide acetals. 64. Acylation of enamino ketones of the indolin-3-one and 2-pyrrolin-4-one series and synthesis of 2-indolyl- and 5-pyrrolylacrylic acid derivatives

The reaction of 2-(N,N-dimethylaminomethylene)indolin-3-one and 2-methyl-3-ethoxycarbonyl-5-(N,N-dimethyl aminomethylene)-2-pyrrolin-4-one with acyl halides was used to synthesize immonium salts, the aqueous hydrolysis of which leads to 2-formyl-3-hydroxyindole and 4-hydroxy-5 formylpyrrole derivatives. -Cyano--(2-indolyl)- and -cyano--(5-pyrrolyl)acrylic acid derivatives were synthesized by reaction of immonium salts of the pyrrole series, 4 acyloxy-5-formylpyrrole and 2-formyl-3-acyloxyindole derivatives, with compounds that contain an active methylene group.See [1] for Communication 63.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 343–348, March, 1991.     

Heterocyclization reactions of azinoisocyanates. Synthesis of 2H-1,2,4-triazol-3(4H)-one derivatives

The reaction of 1-aminoethylidenehydrazones 9 with di-tert-butyl dicarbonate and 4 -dimethylaminopyridine led to the corresponding azinoisocyanates 10 , which underwent thermal rearrangement under the reaction conditions to give 4-(tert-butoxycarbonyl)-5-methyl-2H-1,2,4-triazol-3(4H)-ones 14 . However, amidrazone 17 gave 2-(2-tert-butoxycarbonyloxy-2-phenyl)ethyl-4-(tert-butoxycarbonyl)-5-methyl-2H-1,2,4-triazol-3(4H)-one 22 and N-aziridinyliminocarbamate 18 under the similar conditions.     

Synthesis and reactions of 3-aminothiazolidin-2-thion-4-one derivatives. 6. Thiazolo[4,3-b][1,3,4]thiadiazoles

New thiazolo[4,3-b][1,3,4]thiadiazole derivatives were synthesized. The redistribution of the electron density in their molecules during photoexcitation was analyzed by the methods of quantum chemistry.See [1] for Communication 5.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 484–487, April, 1982.     

Tributylphosphine Catalyzed O -Vinylation of 3-Hydroxy-2-methyl-4 H -pyran-4-one

Protonation of the highly reactive 1:1 intermediates produced in the reaction between tributylphosphine and dimethyl acetylenedicarboxylate by 3-hydroxy-2-methyl-4 H -pyran-4-one leads to vinyltributylphosphonium salts, which undergo an addition-elimination reaction in CH 2 Cl 2 at room temperature to produce dimethyl 2-[(2-methyl-4-oxo-4 H -pyran-3-yl)oxy]-2-butenedioate (1:1 mixtures of E and Z isomers) in fairly good yields.     

4-Hydroxy-2-quinolones. 31. 3-Amino-ir-2-oxo-4-hydroxyquinolines and their acyl derivatives

Abstarct An alternative method has been developed for preparing and studying the antioxidant activity of 3-acylamino-2-oxo-4-hydroxyquinolones. Results are presented from an investigation of the antithyroid and antimicrobial action of the intermediate 2-oxo-3-(1 pyridinio)quinotin-4-olates and the 3-amino-2-oxo-4-hydroxyquinolines.For communication 30, see [1].Ukrainian Pharmaceutical Academy, Khar'kov 310002. Translated from Khimiya Geterotsklicheskikh Soedinenii, No. 8, pp. 1113–1123, August, 1996. Original article submitted June 10, 1996.     

Synthesis and E/Z configuration determination of novel derivatives of 3-aryl-2-(benzothiazol-2'-ylthio) acrylonitrile, 3-(benzothiazol-2'-ylthio)-4-(furan-2'-yl)-3-buten-2-one and 2-(1-(furan-2'-yl)-3'-oxobut-1'-en-2-ylthio)-3-phenylquinazolin-4(3H)-one

Knoevenagel condensation of 2-(benzothiazol-2-ylthio) acetonitrile (2) with either furan-2-carbaldehyde or thiophene-2-carbaldehydes leads to E-isomers 4a-b exclusively, while the condensation of the compound 2 with benzaldehyde or para-substituted benzaldehydes with an electron-donating group afforded E/Z mixtures 4c-e with preferentially formation of the E-isomer. Condensation of furan-2-carbaldehyde (3a) with either 1-(benzothiazol-2'-ylthio) propan-2-one (5) or 2-(2'-oxo propylthio)-3-phenyl-quinazolin-4(3H)-one (9) leads exclusively to the Z-isomers of 6 and 10, respectively. The structures of the newly synthesized compounds were elucidated by elemental analyses, 1H-NMR and 13C-NMR spectra, COSY, HSQC, HMBC, NOE, MS and X-ray crystallographic investigations.     

Reaction of 2-pyridine aldehyde with rhodanines

Reaction of 2-pyridine aldehyde or its methiodide in methanol solution in the presence of piperidine with rhodanine or 3-alkylrhodanines leads to crotenoid condensation and formation of 2-pyridinylidene-5-rhodanine and 2-pyridinylidene-5-(3-alkyl) rhodanines and their monomethiodides.     

Convenient preparation of N-substituted 2-amino-4H-3,l-benzoxazin-4-ones and 3-substituted 2,4(1H,3H)-quinazolinediones

Room temperature treatment of 2-(3-arylureido)benzoic acids ( 1 ) and methyl 2-(3-alkyl-, or 3-arylureido)- benzoates ( 2 ) with concentrated sulfuric acid leads to N-substituted 2-amino-4H-3,l-benzoxazin-4-ones ( 3 ) in generally very good yields. The isomeric 3-substituted 2,4(1H,3H)-quinazolinediones ( 4 ) are conveniently made in high yield by the action of aqueous-ethanolic sodium hydoxide on 2.     

An investigation of the transformations of 2-amino-2-thiazolin-4-one and its derivatives in aqueous solutions

It has been shown by thin-layer radiochromatography that the action of an aqueous solution of alkali on 2-amino-2-thiazolin-4-one and its 5-alkyl derivatives leads predominantly to the opening of the ring by a mechanism similar to the opening of lactams in an alkaline medium.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 44–47, January 1984.     

Research on imidazo[1,2-a]benzimidazole derivatives. 22. Synthesis of 2,3-dihydroimidazo[1,2-a]benzimidazoles starting from 2-imino-3-(2-hydroxyethyl)benzimidazolines

A -elimination reaction with the formation of 2-imino-3-vinylbenzimidazolines occurs simultaneously with intramolecular alkylation and the formation of an imidazoline ring in the action of alcoholic alkali on 2-imino-3-(2-chloroethyl) benzimidazolines. The thermolysis of 3-chlorethyl-substituted imines without a solvent or in an inert solvent leads exclusively to 2,3-dihydroimidazo[1,2-a] benzimidazoles. An attempt to obtain the latter directly from 2-imino-3-(2-hydroxyethyl) benzimidazolines by the action of a mixture of thionyl chloride and acetic anhydride on them also leads to ambiguous results.See [1] for communication 21.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 918–925, July, 1986.