Structures and reactivities of benzo-1,2,3-dithiazolium salts and their selenium analogs

A number of benzo-1,2,3-dithiazolium chlorides (I) and their selenium analogs — benzo-1,2,3-thiaselenazolium, benzo-2,1,3-thiaselenazolium, and benzo-1,2,3-diselenazolium salts — were synthesized. The electronic structures and reactivities of the I cation and salts I–IV are discussed on the basis of a quantum-chemical calculation of cation I and the PMR spectra of salts I–IV. Successive substitution of the sulfur atoms in the I cation by selenium atoms, particularly in the 2 position, substantially increases the degree of transfer of positive charge to the condensed benzene ring. The trend of the nucleophilic reactivities of 6-methoxy derivatives of salts I–IV in the reaction with aromatic amines is the same as the trend of the degree of localization of the positive charge in the 6 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 912–916, July, 1978.     

Reactions of benzo-1,2,3-dithiazolium salts and their selenium analogs with amines

The corresponding 6-arylamino derivatives were obtained by reaction of 6-chloro, 6-bromo, and 6-methoxy derivatives of benzo-1,2,3-dithiazolium and their selenium analogs — benzo-1,2,3-thiaselenazolium, benzo-2,1,3-thiaselenazolium, and benzo-1,2,3-diselenazolium salts — with aromatic amines. The 6-methoxy derivatives also react with acetates of secondary aliphatic amines, whereas in the case of the chloro derivatives attack is directed to the heteroring. 6-Aryl(dialkyl)amino derivatives of dithiazolium and 1,2,3-thiaselenazolium salts are protonated in concentrated sulfuric acid at the exocyclic nitrogen atom. The analogous derivatives of 2,1,3-thiaselenazolium and diselenazolium salts under the same conditions form a tautomeric mixture of dications, the position of the equilibrium between which depends on the substituent. The electronic and PMR spectra of the amination products are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1499–1502, November, 1977.     

Reaction of benzo-1,2,3-dithiazolium salts with aromatic amines

The character of a displaceable group depends substantially on the rate of reaction of substituted 6-chloro and 6-methoxy derivatives of benzo-1,2,3-dithiazolium salts, which gives the corresponding 6-phenylaminobenzo-1,2,3-dithiazolium salts. In 4,6-disubstituted benzo-1,2,3-dithiazolium salts, an aniline residue displaces only the substituent in the 6 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 183–185, February, 1976.     

Synthesis and some properties of benzo-1,2,3-thiaselenazolium salts

The reaction of selenious acid on benzo-1,2,3-dithiazolium salts (Herz salts) gives benzo-1,2,3-thiaselenazolium salts, which were previously obtained from o-aminothiophenols. This reaction, which involves exchange of sulfur by selenium in the heteroring, occurs only under conditions in which the products of hydrolysis of the Herz salts —benzo-3H-1,2,3-dithiazole 2-oxides- are in equilibrium with them.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1361–1364, October, 1976.     

Synthesis of selenium analogs of glycerol from 1,2,3-selenadiazoles

A series of 1-(2-arylethynylselenomercapto)-2,3-epoxypropane and 1,3-di(2-arylethynylselenomercapto)-2-propanol were synthesized starting from 1,2,3-selenadiazoles and epichlorohydrin.     

The preparation and characterization of 5-substituted-4-chloro-1,2,3-dithiazolium salts and their conversion into 4-substituted-3-chloro-1,2,5-thiadiazoles

A series of monosubstituted acetonitriles were treated with disulfur dichloride at room temperature in CH2Cl2 to afford 5-substituted-4-chloro-1,2,3-dithiazolium chlorides 1.Where the 5-substituent was not a good leaving group the chloride salts were converted into the corresponding perchlorate salts 2 which were sufficiently stable and soluble to provide both (1)H- and (13)C-NMR and cyclic voltammetry data. Several of the dithiazolium chlorides were converted into their corresponding 4-substituted-3-chloro-1,2,5-thiadiazoles 13 on treatment with aqueous ammonia. Mechanisms for all reactions are proposed.     

The degradation of 4,5-dichloro-1,2,3-dithiazolium chloride in wet solvents

4,5-Dichloro-1,2,3-dithiazolium chloride 1 (Appel salt) reacts in wet DCM, THF or MeCN to give elemental sulfur, dithiazole-5-thione 4, dithiazol-5-one 5 and thiazol-5-one 6. Furthermore the reaction of 2-phenylthiazol-5(4H)-one 12 with Appel salt 1 at ca. 20 °C gives 4-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)-2-phenylthiazol-5(4H)-one 13 (26%) while at ca. 82 °C a new product 2,2′-diphenyl-4,4′-bithiazol-ylidene-5,5′-dione 14 (36%) is additionally isolated. Finally, 4,4′-bithiazolylidene-5,5′-dione 14 is prepared directly by treating 2-phenylthiazol-5(4H)-one 12 with N-chlorosuccinimide. All new compounds are fully characterised and rational mechanisms are proposed for the formation of all key compounds.     

First heats of solution δH0 of salts in nonaqueous and mixed solvents

A theoretical method is considered for determining H₀ for dissolution of salts in nonaqueous and mixed solvents at various temperatures using published and experimental data for H_m, Values of H₀ were calculated for the dissolution of salts in a number of nonaqueous and mixed solvents at various temperatures. The results obtained were compared with the published data.With an isothermal microcalorimeter, H_m values were determined for the dissolution of potassium nitrate at 25 C in water-glycerol mixtures of various compositions. The results are explained in relation to the structural characteristics of the solvent.     

Reactions of mercury salts with benzo- and tetrafluorobenzobarrelenes

Regiochemistry and stereochemistry of the addition of mercury salts to benzobarrelene and tetrafluorobenzobarrelene have been studied in acetic acid and methanol. The effect of the substrate structure on the regiochemistry of the reaction is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1105–1108, June, 1994.     

Synthesis of 1,2,3-triazole moiety-containing NAD analogs and their potential as redox cofactors

Thirteen 1,2,3-triazole moiety-containing NAD analogs were synthesized and evaluated as redox cofactors. Noticeable enzymatic activities were observed when these analogs were employed as cofactors for malic enzyme or alcohol dehydrogenase. Our results indicated that the natural NAD-dependent oxidoreductases possessed flexible NAD binding pockets.     

Thin-layer chromatography of some organic selenium compounds and their oxygen and sulfur analogs

The Chromatographic behavior of some series of organic selenium compounds and their oxygen and sulfur analogs (urea, thiourea, selenourea; xanthene, thioxanthene, selenoxanthene; xanthone, thioxanthone, selenoxanthone) has been examined by thin-layer chromatography (TLC) on silica gel. The experimental results show the possibility of attaining fast separations on very small amounts of substance (at the microgram level) by simple monodimensional TLC techniques. Urea and its S and Se analogs as well as xanthones are well separated by two- or three-component eluting solvents; xanthenes are not easily screened even by solvent mixtures. The separation of xanthenes from xanthones by the two-dimensional TLC technique is also described. A further result is the possibility of detecting species in trace amounts in the matrix being examined.     

Reaction of N-acylthioureas with electrophilic reagents : Synthesis of 1,3,5-oxadiazinium salts, 1,3,5-thiadiazinium salts, 1,2,4-dithiazolium salts and benzothiazoles

N-Acylthioureas 1 can be easily transformed into 2,4-diamino-6-aryl-1,3,5-oxadiazinium salts 12, 2,4-diamino-6-aryl-1,3,5-thiadiazinium salts 13,3-amino-5-aryl-1,2,4-dithiazolium salts 19 and 2-acylimino-benzothiazolines 22, respectively by reaction with different electrophiles. The structure of the compounds prepared is confirmed by analytical data as well as by chemical transformations.     

Dioxane analogs of flavylium salts

The synthesis of benzodioxane derivatives of 1-benzopyrilium salts is reported and their reaction with nucleophiles is investigated.Taros Shevchenko University, Kiev 252017. Translated from Khimiya Geterotsiklicheskikb Soedinenii, No. 3, pp. 322–324, March, 1995. Original article submitted February 6, 1995.     

2-benzopyrylium salts. 45. Interaction of 2-benzopyrylium salts and their monocyclic analogs with imines of ketones

It was shown that ketonimines, which can have imine--enamine tautomerism, react with pyrylium salts in the enamined form. In such reactions, the 2-benzopyrylium salts are transformed into unsaturated ketones, and their monocyclic analogs are transformed into either quinolizinium salts or pyridinium salts depending on the structure of the initial imine.For the Communication 44, cf. [1].Scientific Research Institute (NII) of Physical and Organic Chemistry, Rostov State University, Roston-on Don 344104. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9 pp. 1176–1185, September, 1994. Original article submitted May 10, 1994.     

Infrared spectral studies of ion association in nonaqueous solutions of cyanide salts with consequences for their nucleophilic reactivity

An infrared spectrometric study of alkali metal and tetraphenylarsonium cyanide (As ⁴ CN) solutions in DMSO or DMF shows that even for concentrations of 0.1M a large proportion of the ions are associated. The order of basicity established through methanol (OH) frequency shifts is CN^–>Cl^–>Br^–. Addition of common ions or cyclic polyether to these solutions, as well as correlations between the (CN^–) frequencies and those of the (CN) bands of CH₃CN bonded to the same cations, suggests assignments of the observed bands to solvated contact ion pairs M⁺ CN^–, triple ions M⁺ CN^– M⁺, and aggregates (M⁺ CN) _n ^– . The nucleophilic reactivity of these salts is related to the structure of these solutions.This article is taken in part from the thesis of A. Loupy, University Paris-Sud Orsay, April 9, 1975, CNRS thesis order No. AO 10102.