1-Substituted aziridine-2,2-dicarboxylic acid esters

The synthesis and chemical properties of aziridine-2,2-dicarboxylic acid esters were investigated. The activation parameters of the inversion of the nitrogen atom in 1-substituted aziridine-2,2-dicarboxylic acid esters were determined. The inv values of a number of substituents attached to the nitrogen atom were established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 346–351, March, 1985.     

Improved method for the synthesis of 1-alkoxyaziridine-2,2-dicarboxylic acid esters

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1136–1137, August, 1990.     

N-alkylation of 1,4-dihydropyridine-3,5-dicarboxylic acid esters

Alkylation of the anions of 1,4-dihydropyridines (1,4-DHP) formed by treatment of sodium hydride in aprotic solvents gave 1-alkyl(up to C₆H₁₃)-3,5-bis(ethoxycarbonyl)- and 1-alkyl-3,5-bis(aryloxycarbonyl)-1,4-DHP. The presence of a substituent in the 4 position increases the reactivity of the 1,4-DHP anion in the alkylation reaction. The absorption maximum in the UV spectra of the 1,4-DHP anion is shifted 100 nm bathochromically as compared with the neutral molecule. The longwave absorption maximum in the UV spectra of 1-alkyl-1,4-DHP is shifted hypsochromically as compared with the 1-unsubstituted compounds; this is explained by steric hindrance of the conjugation of the C=O groups with the -electron system of the ring. The introduction of an alkyl group at the nitrogen atom facilitates the electrical oxidation of 1,4-DHP.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1508–1513, November, 1978.     

Alkyliminomalonic acid and 2-alkyloxaziridine-3, 3-dicarboxylic acid esters

2-Alkyloxaziridine-3, 3-dicarboxylic acid esters have been obtained by oxidizing alkylaminomalonic acid esters by monoperphthalic acid. The activation parameters for the inversion of the nitrogen atom have been obtained for a number of alkyliminomalonic acid and 2-alkyloxaziridine-3, 3-dicarboxylic acid ester.Report 46 from a series entitled Asymmetric Nonbridging Nitrogen. For report 45 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 525–532, April, 1986.     

Preparation of 1H,2H- and 1H-cyclopropene-3,3-dicarboxylic acid esters and 1H,2H-cyclopropene-3,3-dicarboxylic acid from the corresponding trimethylsilyl derivatives

Conclusion The feasibility was shown for use of the silyl protection method for the synthesis of 1H- or 2H-cyclopropene-3,3-dicarboxylic acids and their esters. The preparation of 1H,2H-cyclopropene-3,3-dicarboxylic acid and its dimethyl ester by this method was demonstrated for the first time.For the previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2803–2805, December, 1986.     

Absolute configurations of diastereomeric esters of 1,4-tetrahydrothiazine-3,5-dicarboxylic acid

The reaction of dimethyl 1,4-tetrahydrothiazone-3,5-dicarboxylate with phenyl isocyanate and phenyl isothiocyanate leads to 2,4-dioxo-3-phenyl-9-methoxycarbonyl-7-thia-1,3-diazabicyclo[3.4.O]nonane and its thioxo analog. It is shown that only the trans isomer of the starting diester undergoes the reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1056–1059, August, 1985.     

Synthesis and N-Alkylation of 2-Alkyl-and 2-Arylimidazole-4,5-dicarboxylic acid esters

Nitration of d-tartaric acid, followed by treatment of the resulting dinitrotartaric acid with ammonia and aldehydes gave 2-phenyl-, 2-(2-pyridyl)-, 2-isopropyl-, and 2-isobutylimidazole-4,5-dicarboxylic acids. Some factors affecting the yield of the final products were revealed, and optimal conditions for their esterification were found. N-Alkylation of 2-substituted imidazole-4,5-dicarboxylates thus obtained involves considerable steric hindrances; therefore, the corresponding N-alkyl derivatives can be obtained in a poor yield only in the presence of such a strong base as 1,8-diazabicyclo[5.4.0]undec-7-ene. Original Russian Text A.V. Lebedev, A.B. Lebedeva, V.D. Sheludyakov, E.A. Kovaleva, O.L. Ustinova, V.V. Shatunov, 2007, published in Zhurnal Obshchei Khimii, 2007, Vol. 77, No. 5, pp. 855–859.     

Synthesis and properties of 1-substituted derivatives of diethyl 4-aryl-1,4-dihydrcpyridine-3,5-dicarboxylic acid esters

1-Unsubstituted 4-aryl-3,5-diethoxycarbonyl-1,4-dihydropyridines in the presence of NaH form anions that react with alkyl halides, acid chlorides, and halo acid esters to form the corresponding 1-substituted derivatives of 1,4-dihydropyridine Hydrolysis of one or both ethoxycarbonyl groups in the 3 and 5 positions, as well as hydrolysis of ethyl 4-phenyl-3,5-diethoxycarbonyl-1,4-dihydropyridinyl-1-acetate, occur upon reaction with alkali, but 1,3,5-triethoxycarbonyl-4-phenyl-l,4-dihydropyridine gives the corresponding unsubstituted 1,4-dihydropyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1067–1071, August, 1982.     

Stereoselective trans-N-chlorination of the potassium salt of aziridine-2,2-dicarboxylic acid methyl ester

Primarily trans-1-chloroaziridine is formed in the chlorination of the potassium salt of aziridine-2,2-dicarboxylic acid methyl ester. The silver salt and then the mixed methyl ethyl ester, as well as the trimethylammonium and -phenylethylammonium salts, were obtained from trans-1-chloroaziridine. Signals of diastereomers are observed in the PMR spectrum of the E isomer of the -phenylethylammonium salt; this opens up the fundamental possibility of separation into antipodes.Communication 55 from the series Asymmetric nitrogen. See [1] for communication 54.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 24, No. 3, pp. 324–327, March, 1988.     

Stereoselective electrocatalytic cyclization of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acid esters to form 6-substituted (1R,5R,6R)*-4,4-dialkoxy-5-cyano-2-oxo-3-azabicyclo[3.1.0]hexane-1-carboxylic acid esters

Electrolysis of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acid esters in alcohols in an undivided cell in the presence of NaBr or NaOAc afforded 6-substituted (1R,5R, 6R)*-4,4-dialkoxy-5-cyano-2-oxo-3-azabicyclo[3.1.0]hexane-1-carboxylic acid esters in 80–95% yields. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 102–107, January, 2006.     

Synthesis and oxidation of 2,6-dimethyl-1,4-dihydropyridine-3, 5-dicarboxylic acid esters

Twenty-six esters of 2,6-dihydropyridine-3,5-dicarboxylic acid were obtained by means of the Hantzsch pyridine synthesis. The synthesized compounds were oxidized by chloranil to the corresponding pyridine derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1230–1237, September, 1975.     

2,2′-Dipyridyl-6,6′-dicarboxylic acid diamides: Synthesis,complexation and extraction properties

New ligands for complexing of the post-transition metals – diamides of 2,2′-bipyridyl-6,6′-dicarboxylic acid were developed, synthesised and characterised. They were proposed to be effective extractants towards americium. The structures of the amides were studied in solid as well as in solution. The extraction of Am and lanthanides depending on diamide structure, chlorinated cobalt dicarbollide (CCD) – diamide ratio, type of diluent was studied. The optimal conditions for Am/REE separation were determined. The properties of new potentiometric sensors on the base of 2,2′-dipyridyl-6,6′-dicarboxylic acid diamides were studied. The correlation structure vs. properties of ionophores (i.e. extractants), their sensitivity and selectivity in sensor analysis and extraction are discussed.     

Practical synthetic protocols of enantiopure 1,1-binaphthyl-2,2-dicarboxylic acid and 2,2-dicyano-1,1-binaphthyl starting from optically active dibromide precursor

Dilithiation of optically active 2,2^′-dibromo-1,1^′-binaphthyl 2 with t-BuLi followed by carboxylation of the resulting dilithio-intermediate 3 with CO₂ gave optically active 1,1^′-binaphthyl-2,2^′-dicarboxylic acid 1, which was further transformed to its dicyano derivative 4. Both of these transformations were carried out in a one-pot operation and the products were obtained in excellent yields with no observable racemization.     

Electrocatalytic transformation of dialkyl malonates and arylidene- or alkylidenemalononitriles into dialkyl esters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids

Electrolysis of alcoholic solutions of dialkyl malonates and arylidene- or alkylidenemalononitriles in the presence of NaBr in an undivided cell gave dialkyl esters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids in 60–90% yields. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1547–1552, July, 2005.     

The spatial structure of the isomeric dimethyl esters of 4-hydroxypiperidine-2, 6-dicarboxylic acid

Three isomeric dimethyl esters of 4-hydroxypiperidine-2, 6-dicarboxylic acid have been isolated. The spatial structures of all three isomeric esters and of the acids corresponding to them have been established on the basis of NMR spectra. It has been shown that while the isomers I and II exist in the form of only one conformation each, isomer III in neutral and acid media apparently consists of an equilibrium mixture of two (or more) conformers. The information obtained on the spatial structure of the isomeric esters shows that the cyclization of these compounds with benzylamine and p-nitrobenzaldehyde takes place with the inversion of the piperidine ring.