Synthesis of 3-ketothiophane derivatives

Conclusions 3-Keto-5-alkylthiophane-4-carboxylic acid esters were synthesized by acylation of Meldrum acid with S acetylthioglycolic acid chloride, followed by alcoholysis of 2,2-dimethyl-4,6-dioxo-5-acetylthiomethyl-1,3-dioxane to -(acetylthio)acetoacetic acid esters. These were treated by aldehydes and the crotonic condensation products were cyclized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2042–2045, September, 1986.     

Reaction of arylidene-2-naphthylamines with the ethyl ester of (2-quinolyl)-β-oxopropionic acid

The reaction of arylidene-2-naphthylamines with the ethyl ester of (2-quinolyl)--oxopropionic acid results in the synthesis of ethyl esters of 1-(2-quinolyl)-3-arylbenzo[f]quinoline-2-carboxylic acids. All the theoretically possible intermediate reaction products were isolated: the amino esters of 2-quinoline--oxopropionic acid, the hydroxy esters of tetrahydro- and esters of dihydrobenzo[f]quinoline-2-carboxylic acid, as well as the by-products — the ethyl ester of 2-quinolyl--(R-benzylidene)--oxopropionic acid. The IR, UV, and mass spectra of the synthesized compounds are discussed.Institute of Physical Organic Chemistry, Belorussian Academy of Sciences, Minsk 220603. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1406–1410, October, 1994. Original article submitted October 5, 1994.     

Investigations of vinyl esters of the furan series

The vinyl esters of trans--(2-furyl) acrylic acid, furan-2-carboxylic acid, 5-bromofuran2-carboxylic acid, and 5-nitrofuran-2-carboxylic acid were synthesized by the reaction of the corresponding acids with acetylene and vinyl acetate. Mercuric acetate and boron trifluoride etherate were used as catalysts for the transvinylation of acids of the furan series. The structures of the vinyl esters obtained were proved by IR and PMR spectroscopy. The distribution of the -electron density in the molecules of four of the synthesized vinyl and ethyl esters was studied by means of quantum-chemical calculations by the SCF MO LCAO method (Pople variant) using the Raman and UV absorption spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1443–1447, November, 1972.     

Polarography of furan-2-carboxylic acid esters

The polarographic reduction of furan-2-carboxylic acid esters in dimethylformamide was studied. The E_1/2 values correlate with the * constants for the substituents in the alcohol part of the 2-furoates.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 890–892, July, 1982.     

Research on furan acetal compounds

When 4-alkyl-2-(5-X-2-furyl)-1,3-dioxolanes are heated in the presence of tert-butyl peroxide the acetal ring is opened at the C-O 3–4 bond to give isomeric esters of 5-substituted furan-2-carboxylic acid. The structure of the product was confirmed by means of the UV and IR spectra, gas-liquid chromatography, and alternative synthesis.See [1] for communication VIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1327–1329, October, 1976.     

Synthesis of ortho- and para-quinones of the benzindole series

Ethyl esters of -(3-chloro-1,4-naphthoquinon-3-yl)crotonic or cinnamic acids were obtained by the reaction of 2,3-dichloro-1,4-naphthoquinone with ethyl esters of N-substituted -aminocrotonic or -aminocinnamic acids. These esters were converted by alkaline fusion into benz[f]indole-4,9-dione-3-carboxylic acids, and into ethyl esters of benz[g]indole-4,5-dione-3-carboxylic acid by the action of acetic acid.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 66–68, January, 1989.     

Synthesis of 2h- 1,2,4- benzothiadiazine- 3-carboxylic acid 1,1-dioxide derivatives from 2-sulfamoyloxanilic acid esters

Esters and amides of 2H-1,2,4-benzothiadiazine-3-carboxylic acid 1,1-dioxide were synthesized from 2-sulfamoyloxanilic acid esters.Communication LVIII from the series Research in the Chemistry of Heterocycles. See [1] for communication LVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1056–1059, August, 1976.     

Derivatives of heterocyclic α-iminocarboxylic acids 3. Synthesis of N-alkoxycarbonyl and N-alkoxycarbonylalkenyl derivatives of α-iminocarboxylic acids

By the interaction of L-proline, L-thioproline, pipecolic acid, tetrahydro-1,4-thiazine-3-carboxylic acid, and diastereomeric esters of tetrahydro-1,4-thiazine-3,5-dicarboxylic acid with methyl chloroformate, methyl propiolate, and acetylenecarboxylic acid, we have obtained N-alkoxycarbonyl and N-alkoxycarbonylalkenyl derivatives of -iminocarboxylic acids. By the reaction of N-methoxycarbonyltetrahydro-1,4-thiazine-3-carboxylic acid with hydrazine hydrate, we have obtained 8-amino-7,9-dioxo-4-thia-1,8-diazabicyclo[4.3.0]nonane.For communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1561–1566, November, 1993.     

Fused Polycyclic Nitrogen-Containing Heterocycles: VIII. Friedel–Crafts Intramolecular Cyclization of 5-Phenylthiazole-4-carboxylic Acids—A New Route to Indeno[2,1-d]thiazoles

Friedel–Crafts intramolecular cyclization in the presence of polyphosphoric acid of 2-substituted 5-phenylthiazole-4-carboxylic acids, which are obtained by alkaline hydrolysis of the corresponding esters, leads to indeno[2,1-d]thiazoles. According to the X-ray diffraction data, packing of their molecules in crystal is determined mainly by intermolecular – contacts, regardless of the substituent nature.     

Derivatives of heterocyclic α-iminocarboxylic acids. 4. Reduction of N-alkoxycarbonyl derivatives of α-iminocarboxylic acids

When N-methoxycarbonyl and N-benzoxycarbonyl derivatives of methyl esters of aziridine-2-carboxylic acid, L-proline, L-thioproline, and pipecolic acid interact with NaBH₄ in tert-butanol/methanol, the products of reduction of the C-methoxycarbonyl group of the original compounds are accompanied by bicyclic urethanes and oxazolidines. Reduction of N-maleates and N-fumarates of heterocyclic -iminocarboxylic acids leads to the formation of -hydroxymethyl-N-[4-(2-oxo-2,5-dihydrofuryl)] derivatives of pyrrolidine, piperidine, 1,3-thiazolidine, and 1,4-thiazan. In the latter case, 1-aza-2-hydroxymethyl-4-oxo-5-oxa-9-thiabicyclo [5.4.0]undecene-2 is also obtained. The N-maleates and fumarates of aziridine-2-carboxylic acid are reduced anomalously by sodium borohydride, forming 2-hydroxymethyl-2-(-hydroxyethyl)-3-oxa-1-azabicyclo[3.1.0]hexanes.For Communication 3 see [2].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1567–1573, November, 1993.     

Investigations in the field of vinyl esters of the furan series

The kinetics of the alkaline hydrolysis of vinyl esters of furan-2-carboxylic, trans--(2-furyl)acrylic, and trans-cinnamic acids and also the comparative electrochemical activities of these compounds and of vinyl esters of 5-bromofuran-2-carboxylic, 5-nitro-furan-2-carboxylic, and benzoic acids have been studied by a polarographic method. A symbatic increase in the rate of hydrolysis of the esters with a shift of the potential of the half-wave of reduction into the more negative region has been established. Both the polarity and the polarizability of the molecules have a fundamental influence on the properties of the esters.For Communication X, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 33–36, January, 1974.     

Synthesis and absolute configurations of diastereomeric aziridine-2-carboxylic acid derivatives containing valine and hexafluorovaline fragments

Individual diastereomers of aziridine-2-carboxylic acid esters that contain R- and S-valine and R- and S-hexafluorovaline fragments were isolated by high-performance liquid chromatogrpahy (HPLC). The absolute configurations of both asymmetric centers of the diastereomeric esters were determined on the basis of the parameters of the PMR spectra (AB) and circular dichroism (the sign of the cotton effect at 200–220 nm).Communication 44 from the series Asymmetric unbridged nitrogen. See [1] for communication 43.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1355–1358, October, 1985.     

Unsaturated lactones

New, biologically active pyrazole derivatives containing an unsaturated -lactone ring were obtained by condensation of 2-(1-etboxycarbonyl-1,3-diketopropyl)-2-buten-4-olides with phenylhydrazine and hydrazine hydrate. A number of transformations of the resulting pyrazole-3-carboxylic acid esters were realized.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1611–1614, December, 1978.     

Transformations of pyrrolanthrone-1-carboxylic acid

The preparative possibilities of syntheses based on pyrrolanthrone-1-carboxylic acid were studied. Methylation of the acid or its ester leads to N-methylpyrrolanthrone-1-carboxylic acid esters. The esters were converted to amides and hydrazides, and the latter were converted to 1-amino derivatives through the azides. The indicated transformations and decarboxylation in phosphoric acid give the products in high yields.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 785–788, June, 1978.     

Synthesis of esters of oxocaprylic acids

Conclusions On hydrogenation over Pt-C in the vapor phase (240–250°), esters of -(5-methylfuryl)-propionic acids undergo hydrogenolysis of the C-O bond in the furan ring and are converted into the corresponding esters of-oxocaprylic acid (35–50%) and-oxocaprylic acid (25–35%).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 420–422, February, 1967.     

Rearrangements of 1-oxa-2-azoles. 2. Structure and isomerization of pentamethylene-amidoximes of 4-aminofurazan-3-carboxylic acid

The Z-oxime of the pentamethyleneamide of 4-aminofurazan-3-carboxylic acid isomerizes — rapidly in acid media, slowly in the absence of acid — to the E-oxime which at 120–140C undergoes alkali-catalyzed rearrangement to 4-piperidinofurazan-3-carboxyamidoxime.For Communication 1 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 122–123, January, 1991.     

Synthesis of methyl-substituted pyrano-thiapyrano-, and selenapyrano[2,3-b]pyridines

2H-Pyrano-, 2H-thiapyrano-, and 2H-selenapyrano[2,3-b]pyridines containing a methyl group in the position of the pyridine ring were synthesized by Claisen condensation of the ethyl esters of, respectively, 2-ethoxy-, 2-ethylthio-, and 2-ethylseleno-6-methylpyridine-3-carboxylic acids with ethyl acetate, reduction of the resulting ethyl esters of 2-ethoxy-, 2-ethylthio-, and 2-ethylseleno-6-methylnicotinoylacetic acids with lithium aluminum hydride, and heating of the resulting 2-substituted 3-(, -dihydroxypropyl)-6-methylpyridines with 48% hydrobromic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1539–1540, November, 1972.     

Synthesis and carbene decomposition of functionally substituted diazoacetate esters. 6. Propargyl diazoacetate

A synthesis of propargyl diazoacetate (I) was carried out and its chemical transformations were studied. The reaction of (I) in the presence of Rh(OAc)₂ at 25C with 1-pentyne gives the propargyl ester of l-propylcyclopropene-3-carboxylic acid in 80% yield, while reaction with 2,3-dimethyl-2-butene at 60C results in the propargyl ester of tetramethylcyclopropanecarboxylic acid in 10% yield. Compound (I) reacts under the same conditions (35–60C) with ether, CH₂Cl₂ and water, with the formation of propargyl esters of ethoxyacetic, 2,3-dichloropropionic, and a mixture of glycols and 2-[(propyn-2-yl)-oxycarbonyl]methoxy acetic acids in yields of up to 35%. A spontaneous oligomerization of (I) was observed as a result of a dipolar [1, 3]-cycloaddition of the CH=N₂ fragment of one molecule of (I) to the terminal triple bond of the second molecule with the formation of oligomers of 3-hydroxymethylpyrazole-5-carboxylic acid.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1051–1056, May, 1991.     

Choline esters of alkylenebisphosphonic acids

The reaction of the acid chlorides of alkylenebisphosphonic acids with ethylene glycol and ethylene chlorohydrin gave ethylene glycol and -chloroethyl esters of alkylenebisphosphonic acids. The quaternization of these products leads to choline esters of alkylenebisphosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1424–1429, June, 1990.     

Mechanism of cyclocondensation of isoprenoid acyclic α,Β-enals with monoethyl malonate under the conditions of the Knoevenagel reaction

It was shown that the formation of the di- and trisubstituted derivatives of 1.3-cyclohexadiene-1-carboxylic acid during the condensation of 3-methyl-2-butenal, citral, and farnesal with monoethyl malonate in the presence of secondary amines takes place through the enamines corresponding to these aldehydes, which add to the monoesters of the respective alkenylidenemalonic acids (the normal products of the Knoevenagel reaction) by a mechanism of [4 + 2]-cycloaddition. The free carboxyl group in the dienophile is required for the spontaneous transformation of the intermediate [4 + 2]-cycloadducts into the derivatives of cyclohexadiene-1-carboxylic acid in which the catalyst of the process (the secondary amine) is regenerated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1079–1088, May, 1991.