Condensation of dimedone N-methylimine with isopropylidene arylidenemalonates

Condensation of dimedone N-methylimine with isopropylidene arylidenemalonates has given 4-aryl-1,7,7-trimethyloctahydroqunoline-2,5-diones, characterized by their IR, UV, and PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 786–788, June, 1990.     

Iodonium derivatives of heterocyclic compounds

A method for the preparation of phenyliodonium derivatives of pyrazoles was developed. The reaction of pyrazole and 3,5-dimethyl- and 3,5-diphenylpyrazoles with phenyl iodosoacetate in the presence of p-toluenesulfonic acid gives pyrazole-4-phenyliodonium tosylates, which are converted to pyrazole-4-phenyliodonium betaines on treatment with alkali. The tosylates are converted to pyrazole-4-phenyliodonium chlorides, bromides, and iodides by exchange reactions, and pyrazole-4-phenyliodonium fluorides and borofluorides are obtained by reaction of the betaines with hydrofluoric and fluoboric acids. The ionization constants for a number of phenyliodonium derivatives of pyrazoles were calculated on the basis of the electronic absorption spectra. The 4-phenyliodonium grouping increases the acidity of pyrazoles by 4.5–5 orders of magnitude.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 245–248, February, 1973.     

Polarographic study of heterocyclic ylids of indane-1, 3-dione

The trend of the electrochemical reduction of derivatives of 2-(N-pyridinia)-indane-1,3-dione betaines in both anhydrous dimethylformamide (DMF) and in aqueous DMF solutions was studied by classical polarography, millicoulometry, preparative electrolysis, and cyclical voltammetry. The electrical reduction of the investigated betaines in anhydrous DMF is realized through a step involving the formation of anion radicals. In aqueous DMF solutions the C−N bond undergoes cleavage during the electrical reduction to give indan-1-on-3-ol, the structure of which was established by PMR spectroscopy and mass spectrometry. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 369–375, March, 1980. We thank our senior scientific co-worker é. é. Liepin'sh for interpretation of the PMR spectra.     

Synthesis of 5-substituted 4-methylthio-1,3-thiazoline-2-thiones

Translated from Khimiya Geterotsiklicheskih Soedinenii, No. 2, pp. 276–277, February, 1989.     

Synthesis of 4-ethoxycarbonylmethyl-, 4-N-phenylcarbamoylmethyl-, and 4-carboxymethyl-1,3-dithiole-2-thiones and the corresponding 1,3-dithiolium salts

A method for the preparation of 4-ethoxycarbonylmethyl-, 4-N-phenylcarbamoylmethyl-, and 4-carboxymethyl-1,3-dithiole-2-thiones and the corresponding 1,3-dithiolium salts from -bromoacetoacetic ester, -bromoacetoacetanilide, and sodium tertbutyltrithiocarbonate was developed. The compounds were characterized by their IR and PMR spectra.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 180–183, February, 1984.     

Monoesters of tetrathiafulvalene-2,6(7)-dicarboxylic acid and their use in the preparation of tetrathiafulvalenecarboxylic acid

Monoesters of tetrathiafulvalene-2,6(7)-dicarboxylic acid were synthesized. Decarboxylation of these esters with subsequent hydrolysis gave tetrathiafulvalenecarboxylic acid. Pure mono- and diesters of tetrathiafulvalenedicarboxylic acids were isolated but their assignment to the 2,6- and 2,7-series requires further study.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1630–1633, December, 1984.     

Synthesis and properties of N,N′-bis(1,3-indanedion-2-yl)imidazolium betaine

A method for the synthesis of a new type of onium derivative of 1,3-indanedione — N,N-bis(1,3-indanedion-2-yl)imidazolium betaine — by anhydride condensation of N-(1,3-indanedion-2-yl)-N-carboxymethylimidazolium betaine with phthalic anhydride was developed. The new substance is an acid and forms stable salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 771–774, June, 1991.     

Electronic absorption spectra and acidity of new condensed systems of uracil-derivatives of 1,3-dithiolo[4,5-d]pyrimidine

The first and second ionization constants of certain halouracils and a series of derivatives of a new condensed heterocyclic system — (4H,6H)-1,3-dithiolo[4,5-d]pyrimidine-5,7-dione — were evaluated spectroscopically. Substituents at the 2-position of this system were discovered to have considerable influence on the NH-acidity, which increases in the series of 2-O=, 2-S=, 2-Se=, 2-[(C₂H₅)₂N=]⁺. The stability of the spectrum at pH 14 for the 2-S= and 2-Se= derivatives indicates their unusual stability toward hydrolysis, compared with the 2-O= derivative. The mono- and diionization considerably influence the absorption of the dithiolthione and dithiolselenone system, causing bathochromic shifts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 416–421, March, 1992.