Synthesis and transformations of 1,3-dithiol-2-ylideneisopropylidene malonates

The reaction of 2-alkylthio-1,3-dithiolium salts with Meldrum's acid gave 1,3-dithiol-2-ylideneisopropylidene malonates, which were converted successively to monoethyl esters of 1,3-dithiol-2-ylidenemalonic acids and esters of 1,3-dithiol-2-ylideneacetic acid. 2-Methyl-1,3-dithiolium salts are formed when 1,3-dithiol-2-ylideneisopropylidene malonates are heated with acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1621–1624, December, 1988.     

Synthesis of 6-hydroxytetrahydro-1,3-thiazine-2-thiones and methyl esters of 3-oxoalkyldithiocarbamic acids from 1,3-isothiocyanato ketones

Sodium salts of 3-oxoalkyldithiocarbamic acids were obtained by the reaction of 1,3-isothiocyanato ketones with sodum hydrosulfide. These salts were converted by reaction with methyl iodide into the corresponding dithiocarbamates, and with a mineral acid into the 6-hydroxytetrahydro-1,3-thiazine-2-thiones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 416–419, March, 1991.     

Reaction of 2-aryl-1,3-dioxolanes with nitroacetic ester

Conclusions 2-Phenyl-1,3-dioxolane, and its derivatives with donor substituents in the aromatic ring, react with the methyl ester of nitroacetic acid in Ac₂O medium and in the presence of acid catalysts to give the methyl esters of the corresponding -nitrocinnamic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 439–440, February, 1982.     

Solvatochromism of mesoionic iodo(1,3-dithiol-2-ylium-4-yl)phenolates

Novel mesoionic phenolates were synthesized via 4-hydroxyaryl-1,3-dithiolium salts and characterized spectroscopically by UV-Vis. The bathochromic effect induced by iodine substituents was investigated for several solvents. A negative solvatochromism was recorded for the intramolecular charge transfer absorption band. Correspondence: Lucian M. Birsa, Department of Organic Chemistry, Al.I. Cuza University of Iasi, 700506 Iasi, Romania.     

Silver-catalyzed direct couplings of 2-substituted furans with cyclic 1,3-dicarbonyls

Direct alkenylation of 2-substituted furans with cyclic 1,3-dicarbonyls by means of silver catalysis have been explored. Silver salts resulted more efficient than a variety of Lewis acids and p-TsOH.     

Reactions of 1,3-isothiocyanato ketones with mineral acids. Synthesis of 3,4-dihydro-2H,1,3-thiazin-2-ones

Reactions of 1, 3-isothiocyanato ketones with mineral acids formed 3, 4-dihydro-2H, 1, 3-thiazin-2-ones or their mixtures with 6-alkylidenetetrahydro-1, 3-thiazin-2-ones. Subsequent acid hydrolysis of the thiazines obtained formed salts of 1,3-amino ketones. The direction and extent of the transformation depend on the nature of the acid, reaction temperature, and structure of the 1,3-isothiocyanato ketones.Omsk State University, Omsk 644077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 850–854, June, 1996. Original article submitted October 18, 1995.Deceased.     

Synthesis of 1,3-dialkylimidazolium-2-carboxylates by direct carboxylation of 1,3-dialkylimidazolium chlorides with CO2

1,3-Dialkylimidazolium-2-carboxylates 1a and 1b are obtained in good to excellent yield and selectivity by carboxylation of the corresponding 1,3-dialkylimidazolium chloride salts with a CO₂/Na₂CO₃ system at temperatures ranging from 80 to 135 °C. The effect of temperature and reaction time on the yield and the selectivity of the carboxylation products has been studied. Coupling the CO₂-based synthesis of 1,3-dialkylimidazolium-2-carboxylates with the transcarboxylation reaction described earlier [Tommasi, I.; Sorrentino, F.; Tetrahedron Lett., 2005, 46, 2141] allows us to set up a new synthetic procedure for the synthesis of organic carboxylates and alkylcarbonate anions avoiding the use of strong bases.     

Fluoroalkyl-containing 2-arylhydrazono-1,3-dicarbonyl compounds in the reactions with ethylenediamine and polyethylenepolyamines

Acyclic N,N′-(poly)ethylene-bis(2-arylazo-1,3-aminovinylketones) are the main products in the reactions of fluoroalkyl-containing 2-arylhydrazono-1,3-diketones with ethylenediamine, diethylenetriamine and triethylenetetramine. Nickel(II) and copper(II) chelates were obtained from N,N′-ethylene-bis(2-arylazo-1,3-aminovinylketones). 2-Arylhydrazono-3-fluoroacyl esters formed N,N′-ethylenediamides of 2-arylhydrazono-3-fluoroacylpropionic acids with ethylenediamine. Interaction of 2-arylhydrazono-3-fluoroacyl esters with diethylenetriamine and triethylenetetramine resulted in and decomposition products.     

Enamino derivatives of 1,3-dioxoindane-2-carboxylic acid

Although 1,3-dioxoindane-2-carboxylic acid is highly unstable, its enamino derivatives can be isolated by careful hydrolysis of their esters with 2,4-dihydroxy-1,4-naphthoquinone. Crystal structure determination reveals the formation of two intramolecular hydrogen bonds, offering thus a possible explanation for the stability of these acids.     

Synthesis and transformations of derivatives of 2-aryl-5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carboxylic acid

On the basis of methyl esters of 2-aryl-5-hydrazino-1,3-oxazole-4-carboxylic acids the earlier unknown methyl esters of 2-aryl-5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carboxylic acids as well as their functional derivatives were synthesized. The latter were used for further transformations, in particular, for introducing the residues of highly basic aliphatic amines into the 5 position of oxazole, and the oxazol-2-yl moiety into the 4 position of the oxazole ring.     

Sulfur-containing derivatives of thiolan-1,1-dioxide 3. Reactions of salts of 2-(n,n-dialkyl)iminio-5,5-dioxoperhydrothieno[3,4-d]-1,3-dithiolans with bases

Salts of condensed 2-(N,N-dialkyl)iminio-1,3-dithiolan and 1,1-dioxothiolan rings are converted in alkaline media to 1,1-dioxothiolen esters of N,N-dialkyldithiocarbamic acids and into unsaturated bicyclic compounds. The latter are formed when the initial salts contain a bromine atom to the sulfonyl group.For Communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 40–47, January, 1993.     

Flash vacuum pyrolysis of 1-methoxy-1,3-bis(trimethylsiloxy)-1,3-dienes: synthesis of α-allenic acids.

Flash vacuum pyrolysis at 680–700°C of 2- and 4- substituted 1-methoxy-1,3-bis (trimethylsiloxy)-1,3-butadienes yields α-allenic silyl esters which, upon hydrolysis, provide a direct route to α-allenic acids with good overall yield.     

Tetrahydrochromenylium and -Thiochromenylium Salts from Triketones of the 2-(3-Oxopropyl)cyclohexane-1,3-dione Series

We have worked out the optimal conditions for synthesis of 2,4-diaryl-5-oxo-5,6,7,8-tetrahydrochromenylium and -thiochromenylium salts based on triketones of the 2-(1,3-diaryl-3-oxopropyl)cyclohexane-1,3-dione series. For the first time, along with 5-oxo-substituted salts, we have obtained 5-thioxo-5,6,7,8-tetrahydrothiochromenylium salts. A necessary condition for the formation of the latter on treatment with acids and S-nucleophiles is the presence of electron-donor groups on the aryl substituents of the indicated triketones.     

Synthesis of 2-phenylethynyl-1,3-dioxanes and their hydrolysis

2-Phenylethynyl substituted 1,3-dioxanes were obtained by the reaction of 1,3-dioxanium salts with an lotsich reagent. It was shown that they are readily hydrolyzed with the formation of a-acerylenic ketones. A simple new method is proposed for the synthesis of the latter without isolating the intermediate 1,3-dioxanes using the reaction of 4 substituted 2-methyl(phenyl, furyl)-1,3-dioxanium salts with hydroxymethyl- and phenylethynylmagnesium bromide as examples.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 193–197, February, 1996.     

Regioselective carbon-carbon bond formation at C2 of 1,3-thiazole by reaction of n-ethoxycarbonylthiazolium chloride with C-nucleophiles

N-Ethoxycarbonylthiazolium chloride generated $\text{in situ}$ from 1,3-thiazole and ethyl chloroformate, treated with lithium carbanions of esters, Grignard reagents, silyl enol ethers and esters, undergo nucleophilic addition at C₂ affording the corresponding 2-substituted N-ethoxycarbonylthiazolines.     

Linear codimerization of 2-cyclopropyl-1,3-butadiene with methyl acrylate catalyzed by iron and cobalt complexes

Conclusions The linear codimerization of 2-cyclopropyl-1,3-butadiene with methyl acrylate gave a mixture of methyl esters of 5-cyclopropyl-2Z,5Z- and 2E,5Z-heptadienoic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2364–2366, October, 1984.     

Interaction of (z)-4-bromo-1,3-di(2-thienyl)- 2-buten-1-one with amines,synthesis of di(2-thienyl)azolo[<Emphasis Type="Italic">a</Emphasis>]pyridines

(Z)-4-Bromo-1,3-di(2-thienyl)-2-buten-1-one was obtained by the bromination of 1,3-di(2-thienyl)-2-buten-1-one by NBS in anhydrous CCl₄. The starting butanone was obtained by the condensation of 1-(2-thienyl)-1-ethanone by the action of SOCl₂. The reaction of (Z)-4-bromo-1,3-di(2-thienyl)-2-buten-1-one with tertiary amines such as Et₃N, pyridine, 1-alkyl-1,3-diazole, 1-alkylbenzimidazole, and 1-alkyl-1,2,4-triazole leads to quaternary salts. The azolium salts cyclize by the action of base to give di(2-thienyl)azolo[a]pyridinium derivatives. 3-Methyl-6,8-di(2-thienyl)[1,3]thiazolo[3,2-a]pyridin-4-ium and 2,4-di(2-thienyl)pyrido[2,1-b]benzothiazol-10-ium bromides were obtained by the same procedure but without separating the intermediate quaternary salts.     

Efficient Electrochemical Deprotection of Carboxylic and Amino Acids from Their 2-(Hydroxymethyl)-1,3-dithiane (Dim) Esters

Carboxylic acids and amino acids are electrochemically deprotected from their 2-(hydroxymethyl)-1,3-dithiane (Dim) esters.     

Preparation and polymerization of some vinyl monomers containing the 2-oxo-1,3-dioxolane group

The syntheses and polymerizations of (2-oxo-1,3-dioxolan-4-yl)methyl acrylate, 4-(2-oxo-1,3-dioxolan-4-yl)methyl itaconate, and (2-oxo-1,3-dioxolan-4-yl)methyl maleate are described. Reactivity ratios in the copolymerization of these monomers with other comonomers are reported and the Alfrey-Price Q and e values calculated. The post-polymerization effects of ultraviolet light and heat on these polymers and copolymers are presented and compared to those for similar polymers containing the 2,2-dimethyl-1,3-dixolane groups, which performs as an internal ultraviolet sensitizer. The 2-oxo derivatives are crosslinked thermally but not by ultraviolet light. The crosslinking reaction can be catalyzed by acids, bases, and salts.     

Reaction of Long-Chain Vanillyl Esters with CH-Acids and 2-Naphthylamine

The previously unknown 4-(alkyl-11-oxo-7,8,9,10,11,12-hexahydrobenzo[a]acridin-12-yl)- and 4-(alkyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)-2-methoxyphenyl esters of aliphatic (C₅-C₇, C₁₂) carboxylic acids were synthesized via cascade heterocyclization of cyclohexane-1,3-dione and dimedone with 2-naphthylamine and long-chain vanillyl esters.