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Journal articles on the topic '(dioxo)'

Author: Grafiati

Published: 4 June 2021

Last updated: 9 February 2022

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1

Daci-Ajvazi, Majlinda, Sevdije Govori, and Shuhreta Omeragiq. "Synthesis and Microbiological Activity of Some Newly Synthesized Derivatives of 2-Oxo-2H-chromen-2-one." E-Journal of Chemistry 8, no. 4 (2011): 1522–27. http://dx.doi.org/10.1155/2011/402975.

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By the action of 2-amino-5-methylthio-1,3,4-thiadiazole, 3-amino-5-methylisoxazole, 2-amino-6-fluorobenzothiazole, 2-amino-5-chloropyridine, respectively, on 4-chloro-2-oxo-2H-chromene-3-sulfonyl chloride, the corresponding 9-methylthio-7,7-dioxo-7,7a-dihydro-5-oxo-7λ6,10-dithia-8,11-diaza-cyclopenta[b] phenantren-6-one, 9-methyl-7,7-dioxo-7H-5,8-dioxa-7λ6-thia-7a,11-diaza-cyclopenta[b] phenantren-6-one, 9-fluoro-7,7-dioxo-7H-5-oxa-7λ6,12-dithia-7a,13-diaza-indeno[1,2-b] phenantren-6-one and 9-Chloro-7,7-dioxo-7H-5-oxa-7λ6-thia-7a,12-diaza-benzo[α]anthracen -6-one were formed and they have bee

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2

Neda, Ion, Michael Farkens, Axel Fischer, Peter G. Jones та Reinhard Schmutzler. "Zur Chemie der 4,6-Dioxo-1,3,5,2-triazaphosphinane, Teil III. Darstellung von 4,6-Dioxo-1,3,5,2 λ3-, 4,6-Dioxo-1,3,5,2 λ4- und 4,6-Dioxo-1,3,5,2 λ5-triazaphosphinanen / Chemistry of the 4,6-Dioxo-1,3,5,2 λ3-triazaphosphinanes, Part III. Synthesis of 4,6-Dioxo-1,3,5,2 λ3-, 4,6-Dioxo-1,3,5,2 λ4-, and 4,6-Dioxo- 1,3,5,2 λ5-triazaphosphinanes". Zeitschrift für Naturforschung B 48, № 4 (1993): 443–51. http://dx.doi.org/10.1515/znb-1993-0408.

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In the reaction of 2-chloro-1,3,5-trimethyl-4,6-dioxo-1,3,5,2 λ3-triazaphosphinane (1) with β-chloroethylamine hydrochloride and bis-(β-chloroethyl)amine hydrochloride, 1,3,5-trimethyl-2-(β-chloroethyl)amino-4,6-dioxo-1,3,5,2 λ3-triazaphosphinane (4) and 1,3,5-trimethyl-2-bis-(β-chloroethyl)amino-4,6-dioxo-1,3,5,2 λ3-triazaphosphinane (5) were obtained. The reaction of 4 and 5 with sulfur, hexafluoroacetone, tetrachloroorthobenzoquinone and 4-nitrobenzoyl azide gave the 1,3,5-trimethy1-4,6-dioxo-1,3,5,2 λ4-triazaphosphinanes 6 and 9 and the 1,3,5-trimethyl-4,6-dioxo-1,3,5,2 λ5-triazaphosphinan

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3

Leng, Xin, Bingqin Yang, Pengfei Zhang, and Xianwen Fang. "4-Methyl-2,7-dioxo-3,6-dioxa-1(1,1′)-ferrocenacycloheptaphane." Acta Crystallographica Section E Structure Reports Online 67, no. 7 (2011): m947. http://dx.doi.org/10.1107/s1600536811019398.

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4

Boluda, Carlos J., Juan M. Trujillo, José A. Pérez, Hermelo López, Zulma Aragón, and Raquel G. Díaz. "Semisynthesis of Justicidone and a 1,2-Quinone Lignan. Cytotoxic Activity of Some Natural and Synthetic Lignans." Natural Product Communications 4, no. 2 (2009): 1934578X0900400. http://dx.doi.org/10.1177/1934578x0900400214.

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The dioxo-lignans of the arylnaphthalene-type named justicidone (2) and elenodione (3) were obtained from elenoside (1) through a short and efficient semisynthetic process. Justicidone (2), one of its synthetic precursors, 4-(benzo[d][1,3]dioxol-5-yl)-5,6,8-trimethoxy-3a,4-dihydronaphtho[2,3-c]furan-1(3H)-one (9), and the aglycone of elenoside (5) showed cytotoxic activity towards the HL-60 cell line (IC50 = 7.25 μM, 5.41 μM and 2.06 μM, respectively).

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5

Gingl, Franz, та Joachim Strähle. "Synthese und Struktur von μ-Bromo-μ-dioxo-bis( phthalocyaninato-niob(V))tribromid, [(PcNb)2O2Br]+Br3-, einem zweikernigen Phthalocyaninatokomplex / Synthesis and Structure of μ-Bromo-μ-dioxo-bis(phthalocyaninato-niobium(V))tribromide, [(PcNb)2O2Br]+Br3-, a Dinuclear Phthalocyaninato Complex". Zeitschrift für Naturforschung B 44, № 2 (1989): 110–16. http://dx.doi.org/10.1515/znb-1989-0202.

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Abstract dioxo-bis(phthaIocyaninato-niob(V))tribromid, [(PcNb)20 2Br]+BrJ, einem zweikernigen Phthalocyaninatokomplex Synthesis and Structure of i w-Bromo-/ i/-dioxo-bis(phthalocyaninato-niobium(V))tribromide, [(PcNb)20 2Br]~Br3 , i w -Brom o-^-dioxo-bis(phthalocyaninato-niobium (V))tribrom ide. Synthesis. Crystal Structure

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6

NEDA, I., M. FARKENS, A. FISCHER, P. G. JONES та R. SCHMUTZLER. "ChemInform Abstract: 4,6-Dioxo-1,3,5,2λ3-triazaphosphinanes. Part 3. Synthesis of 4, 6-Dioxo-1,3,5,2λ3-, 4,6-Dioxo-1,3,5,2λ4-, and 4,6-Dioxo- 1,3,5,2λ5-triazaphosphinanes." ChemInform 24, № 32 (2010): no. http://dx.doi.org/10.1002/chin.199332201.

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7

Ayambekam, Fazilat, and Majid Ghashang. "Preparation of skeletally diverse quinazoline-2,4(1H,3H)-diones using Na2SiO3/SnFe2O4 catalytic system through a four-component reaction." Main Group Metal Chemistry 43, no. 1 (2020): 77–83. http://dx.doi.org/10.1515/mgmc-2020-0008.

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AbstractSodium silicate with the formula of Na2SiO3 was used for the four-component reaction of ketones, aldehydes and cyanoacetamide. The effect of SnFe2O4 nano-particles on the catalytic potential of Na2SiO3 was investigated. The desired products synthesized by this method are 5-amino-7-aryl-2,4-dioxo-2,3,4,4a,7,7a,8,9,10,11-decahydro-1H-benzo[i]quinazoline-6-carbonitriles, 5-amino-2,4-dioxo-7-aryl-1,2,3,4,4a,7,7a,8,10,11-decahydropyrano[3,4-i] quinazoline-6-carbonitrile, 5-amino-9-methyl-2,4-dioxo-7-aryl-2,3,4,4a,7,7a,8,9,10,11-decahydro-1H-pyrido[3,4-i] quinazoline-6-carbonitrile and 5-ami

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8

Kuhn, Norbert, Ahmad Al-Sheikh, Simon Schwarz, and Manfred Steimann. "Zwitterionische Imidazolium- und Phosphonium-Derivate der Methylenmeldrumsäure [1,2] / Zwitterionic Imidazolium and Phosphonium Derivatives of Methylene-Meldrum’s Acid [1,2]." Zeitschrift für Naturforschung B 60, no. 4 (2005): 398–402. http://dx.doi.org/10.1515/znb-2005-0407.

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2,2-Dimethyl-4,6-dioxo-5-pyridinomethyl-1,3-dioxan-5-yl-pyridinium ylide (9) reacts with 2,3-dihydro- 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1; R1 = iPr, R2 = Me) to give the zwitterionic imidazolium derivative 2,2-dimethyl-4,6-dioxo-5-(1,3-diisopropyl-4,5-dimethylimidazoliomethyl)- 1,3-dioxan-5-yl-imidazolium ylide (4) in good yield. Similarly, the phosphonium compound 2,2-dimethyl-4,6-dioxo-5-triphenylphosphoniomethyl-1,3-dioxan-5-yl-phosphonium ylide (5) is obtained from 9 and PPh3. The crystal structures of 4 and 5 are reported

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9

Wahyuningsih, Tutik Dwi, and Yehezkiel Steven Kurniawan. "Synthesis of Dioxo-Dioxane and Dioxo-Dioxepane Ethyl Oleate Derivatives as Bio-Lubricant Base Stocks." Indonesian Journal of Chemistry 20, no. 3 (2020): 503. http://dx.doi.org/10.22146/ijc.42317.

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In this study, two novel compounds, i.e., ethyl 8-(3-octyl-5,6-dioxo-1,4-dioxan-2-yl)octanoate and ethyl 8-(3-octyl-5,7-dioxo-1,4-dioxepan-2-yl)octanoate were prepared from oleic acid as the starting material. Both compounds were obtained from the esterification of the ethyl 9,10-dihydroxyoctadecanoate with dicarboxylic acids in the presence of p-toluenesulfonic acid as a catalyst. The chemical structures of the synthesized products were confirmed by FTIR, 1H-NMR, and MS spectrometers. The bio-lubricant properties of the products, such as density, total acid number, total base number, and iodi

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10

Senge, Mathias O., and Kevin M. Smith. "Metal Complexes of Dioxo-porphyrins-Zinc(II) Complexes of 2,3,7,8,12,13,17,18-Octaethyl-5,15-dioxo-porphyrin and 5,15-Dioxo-etioporphyrin I." Zeitschrift für Naturforschung B 48, no. 7 (1993): 991–99. http://dx.doi.org/10.1515/znb-1993-0724.

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The crystal structures of two zinc(II) 5,15-dioxo-porphyrins (porphodimethenes) have been determined to investigate the coordination chemistry of porphyrins with interrupted conjugation system. Both compounds have a five-coordinated zinc center with pyridine as axial ligand and show overall structural parameters very similar to porphyrins. The oxidized meso-positions are, however, easily identified by longer Cm–Ca bond lengths and smaller Ca–Cm–Ca angles. The macrocycles exhibit a small degree of conformational distortion, and the etioporphyrin I derivative shows evidence for π-stacking in the

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11

Maddi, N. V. D. Harikiran, Srinivas Garaga, Ambati V. Raghava Reddy, Paul Douglas Sanasi, and Raghubabu Korupolu. "Synthesis and characterization of related substances of Azilsartan Kamedoxomil." Current Issues in Pharmacy and Medical Sciences 30, no. 1 (2017): 31–35. http://dx.doi.org/10.1515/cipms-2017-0007.

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Abstract Azilsartan Kamedoxomil is an AT1-subtype angiotensin II receptor blocker (ARB). During the laboratory synthesis of Azilsartan Kamedoxomil, four related substances of Azilsartan Kamedoxomil were observed and identified. These were 2-Ethoxy-3-[[4-[2- [4-[(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl]-5-oxo-1,2,4-oxadiazol-3-yl]phenyl]phenyl] methyl] benzimidazole-4-carboxylic acid (azilsartan N-medoxomil, 9), (5-methyl-2-oxo- 1,3-dioxol-4-yl)methyl 2-ethoxy-3-[[4-[2-[4-[(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl]-5- oxo-1,2,4-oxadiazol-3-yl]phenyl]phenyl] methyl] benzimidazole-4-carboxylate (azils

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12

Leng, Xin, Bingqin Yang, Lin Cui, and Bo Liu. "6-(4-Methylphenyl)-2,10-dioxo-3,9-dioxa-6-aza-1(1,1′)-ferrocenacyclodecaphane." Acta Crystallographica Section E Structure Reports Online 66, no. 12 (2010): m1528. http://dx.doi.org/10.1107/s1600536810043278.

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13

Modro, Agnes M., and Tomasz A. Modro. "2-Chloro-2,4-dioxo-3-methyl-1,3,2-thiazaphospholidine. Comments on its phosphorylating properties." Canadian Journal of Chemistry 70, no. 10 (1992): 2552–54. http://dx.doi.org/10.1139/v92-323.

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2-Alkoxy-2,4-dioxo-3-methyl-1,3,2-thiazaphospholidines undergo facile ring-opening reactions with chloride ion, and, in particular, with water. This reactivity may limit their value as first intermediates in the sequential synthesis of phosphoric diesters from the parent 2-chloro-2,4-dioxo-3-methyl-1,3,2-thiazaphospholidine.

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14

Kuhn, Norbert, Ahmed Al Sheikh, and Manfred Steimann. "Synthesis and Structure of a Zwitterionic Imidazolium 1,3-Dioxanide." Zeitschrift für Naturforschung B 58, no. 8 (2003): 817–19. http://dx.doi.org/10.1515/znb-2003-0818.

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{Bis(methylthio)methylene}-2,2-dimethyl-4,6-dioxo-1,3- dioxane (7) reacts with cis-1,2-diamino-1,2-dicyanoethene to give 2,2-dimethyl-4,6-dioxo-5-{2-(4,5-dicyano)} imidazolio-1,3-dioxan-5-yl-imidazolium ylide (8) as a stable crystalline solid in good yield. The crystal structure of 8 × C3H6OS is discussed.

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15

Zhang, Biaobiao, and Licheng Sun. "Why nature chose the Mn4CaO5 cluster as water-splitting catalyst in photosystem II: a new hypothesis for the mechanism of O–O bond formation." Dalton Transactions 47, no. 41 (2018): 14381–87. http://dx.doi.org/10.1039/c8dt01931b.

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In this new hypothesis, we propose a complete catalytic cycle involving a charge-rearrangement-induced Mn<sup>VII</sup>–dioxo species on the dangling Mn4 during the S<sub>3</sub> → S<sub>4</sub> transition. The O–O bond is formed within this Mn<sup>VII</sup>–dioxo site.

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16

Smicius, Romualdas, Virginija Jakubkiene, Milda M. Burbuliene, Aiste Mikalainyte, and Povilas Vainilavicius. "Synthesis of 1-(6-Methyl-2,4-Dioxo-1,2,3,4-Tetrahydro-3-Pyrimidinyl)Acetyl-4-Alkyl(Aryl)Thiosemicarbazides and their Heterocyclisation to 1,2,4-Triazoles and 1,3,4-Thiadiazoles." Journal of Chemical Research 2002, no. 4 (2002): 170–72. http://dx.doi.org/10.3184/030823402103171555.

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5-(6-Methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)methyl-1,3,4-oxadiazole-2-thione reacts with amines to give 1-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)acetyl-4-alkyl(aryl)thiosemicarbazides, which on treatment with base or acid undergo cyclisation to 4-alkyl-1,2,4-triazole-2-thiones or 4-amino-1,3,4-thiadiazoles, respectively.

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17

Boukthir, Mouna, Zribi Fethi, Iman Halloum, Laurent Kremer, and Fakher Chabchoub. "Synthesis and Antitubercular Evaluation of Some Novel 1,2,3,6-tetrahydropyrimidine-5-carbonitrile." JOURNAL OF ADVANCES IN CHEMISTRY 9, no. 3 (2013): 2072–77. http://dx.doi.org/10.24297/jac.v9i3.1014.

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In an attempt to find a new class of antitubercular agents, a series of 1,2,3,6-tetrahydropyrimidine-5-carbonitrile were prepared via the reaction of ethyl N-ethoxycarbonylbenzimidate 2a-b with cyanoacetanilide derivatives 1a-c. These compounds were screened for their antitubercular activity against M. tuberculosis. Several analogues, such as 2,6-dioxo-1-phenyl-4-p-tolyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3a, 1-benzyl-2, 6-dioxo-4-p-tolyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3c and 1-benzyl-2, 6-dioxo-4-phenyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3d exhibited a potent an

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18

Elix, John A., та Judith H. Wardlaw. "Lusitanic Acid, Peristictic Acid and Verrucigeric Acid. Three New β-Orcinol Depsidones from the Lichens Relicina sydneyensis and Xanthoparmelia verrucigera". Australian Journal of Chemistry 53, № 9 (2000): 815. http://dx.doi.org/10.1071/ch00121.

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Three new β-orcinol depsidones belonging to the stictic acid chemosyndrome, namely peristictic acid (1,4-dihydroxy-10-methoxy-5,8-dimethyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepin-11-carboxylic acid) (9), lusitanic acid (methyl 1,4-dihydroxy-10-methoxy-5,8-dimethyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepin-11-carboxylate) (10) and verrucigeric acid (1,4-dihydroxy-11-hydroxymethyl-10-methoxy-5,8-dimethyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepin-1,11-diyl hydrogen orthoacetate) (14) have been identified in the lichens Relicina sydn

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19

Ghafuri, Hossein, Fatemeh Ganjali, and Peyman Hanifehnejad. "Cu.BTC MOF as a Novel and Efficient Catalyst for the Synthesis of 1,8-Dioxo-octa-hydro Xanthene." Chemistry Proceedings 3, no. 1 (2020): 2. http://dx.doi.org/10.3390/ecsoc-24-08359.

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: A copper-based metal-organic framework with 1,3,5-tricarboxylic acid linkers was prepared through a facile hydrothermal method. This MOF has not been used in organic reactions widely. Cu.BTC was employed as an affordable, competent heterogeneous catalyst in 1,8-dioxo-octa-hydro xanthene synthesis. Additionally, the structure, morphology, and porosity of this catalyst were considered. Various techniques such as FE-SEM, BET, EDS, FT-IR, and XRD applied to this aim. As a result, Cu.BTC had a mesoporous structure, an excellent specific surface area, and high purity. Some privileges of using this

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20

Kuhn, Norbert, Ahmed Al-Sheikh, and Manfred Steimann. "2-Amino-1,3-dimethylimidazolium 2,2-Dimethyl-4,6-dioxo-1,3-dioxanide. First Structural Characterisation of the Anion of Meldrum’s Acid [1]." Zeitschrift für Naturforschung B 58, no. 5 (2003): 481–84. http://dx.doi.org/10.1515/znb-2003-0519.

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2-Amino-1,3-dimethylimidazolium 2,2-dimethyl- 4,6-dioxo-1,3-dioxanide (6) has been obtained from the reaction of 2,2-dimethyl-4,6-dioxo-1,3- dioxan (1, “Meldrum’s acid”) and 2-imino-1,3-dimethylimidazoline (5) in excellent yield. The unit cell of 6 contains two crystallographically independent anions lying on crystallographic mirror planes. The structure of the anion is compared with that of compound 1.

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21

Kuhn, Norbert, Ahmed Al-Sheikh, and Manfred Steimann. "Synthesis and Structure of 1-{2,2-Dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3- dioxan-5-yl}pyridinium Ylide: A New Route to Meldrum’s Acid Derivatives." Zeitschrift für Naturforschung B 58, no. 5 (2003): 381–84. http://dx.doi.org/10.1515/znb-2003-0504.

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2-Bromo-5,5-dimethyl-4,6-dioxo-1,3-dioxine (3) reacts with pyridine and aqueous potassium carbonate to give 1-{2,2-dimethyl-4,6-dioxo-5-(1-pyridinio)-1,3-dioxan-5-yl}pyridinium ylide (5). The crystal structure analysis confirms the betaine nature of 5 consisting of two distored ring fragments [interplanar angle 58.0(4)°] connected by a C-N single bond [1.440(1) Å ].

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22

Klásek, Antonín, Stanislav Kafka, and Thomas Kappe. "Synthesis and Some Reactions of 3-Substituted 1,4-Bis(4-hydroxy-2-oxo-1,2-dihydroquinolin-6-yloxy)butanes." Collection of Czechoslovak Chemical Communications 60, no. 12 (1995): 2137–46. http://dx.doi.org/10.1135/cccc19952137.

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Condensations of 1,4-bis(4-aminophenoxy)butane Ia and its N,N'-dimethyl derivative Ib with substituted diethyl malonates gave 1,4-bis(4-hydroxy-2-oxo-1,2-dihydroquinolin-6-yloxy)butanes IIa-IIf. From these compounds, 1,4-bis(3-halogeno-2,4-dioxo-1,2,3,4-tetrahydroquinolin-6-ylox y)butanes IIIa-IIIg and 1,4-bis(3-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinolin-6-yloxy )butanes IIIh-IIIm were prepared.

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23

Bodwell, Graham J., Tom J. Houghton, and David Miller. "Synthesis, structure and AM1 conformational study of 1,12-dioxa-2,11-dioxo[3.3]orthocyclophane." Tetrahedron Letters 38, no. 9 (1997): 1469–72. http://dx.doi.org/10.1016/s0040-4039(97)00132-9.

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24

Zhou, Bao-Han, Li-Ping Cao, Yu-Zhou Wang, and Meng Gao. "Diethyl 2,13-dioxo-16,18-dioxa-1,3,12,14-tetraazapentacyclo[10.7.2.03,21.05,10.014,20]undeca-5,7,9-triene-20,21-dicarboxylate." Acta Crystallographica Section E Structure Reports Online 63, no. 1 (2006): o65—o66. http://dx.doi.org/10.1107/s1600536806050926.

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25

Buist, Amanda R., Alan R. Kennedy, and Craig Manzie. "Four salt phases of theophylline." Acta Crystallographica Section C Structural Chemistry 70, no. 2 (2014): 220–24. http://dx.doi.org/10.1107/s2053229614000825.

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The structures of two anhydrous salt phases of theophylline, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium tetrafluoroborate, C7H9N4O2+·BF4−, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride, C7H9N4O2+·Cl−, are reported together with the structures of two monohydrate salt forms, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride monohydrate, C7H9N4O2+·Cl−·H2O, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium bromide monohydrate, C7H9N4O2+·Br−·H2O. The monohydrate structures are mutually isostructural, with the cations and anions lying on crystallographic mirror planes (Z′ = 1\over 2). The main in

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26

ABDEL-RAZIK, H. H., H. A. ALMAHY, and Y. A. EL-BADRY. "NEW TETRA (1,4-DITHIN)PORPHYRAZINES AND THEIR APPLICATION AS PHOTOCATALYSTS FOR PURIFYING ENVIRONMENTAL WATERS: AN APPROACH TO GREEN CHEMISTRY." Periódico Tchê Química 15, no. 30 (2018): 259–67. http://dx.doi.org/10.52571/ptq.v15.n30.2018.262_periodico30_pgs_259_267.pdf.

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2,3-Dichloro-5,6-dimethylbenzoquinone reacted with di(sodiothio)maleonitrileto produce heterocyclic thianone, 6,7-dimethyl-5,8-dioxo-5,8-dihydro-1,4-benzodithin-2,3-dicarbonitrile which was cyclo-tetramerizedin the presence of lithium/pentanol and acetic acid producing tetra 6,7-dimethyl-5,8-dioxo-5,8-dihydro-1,4benzodithin-porphyrazine (2H-Pz). Likewise, the dicarbonitrile compound was cyclo-tetramerized in the presence of metal salt and quinoline affording tetra 6,7-dimethyl-5,8-dioxo-5,8-dihydro-1,4-benzodithinporphyrazinato-metal II (M-Pz), M is Co, Ni or Zn. Photoactivity of the synthesiz

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27

Eller, Gernot A., Gytė Vilkauskaitė, Algirdas Šačkus, et al. "An unusual thionyl chloride-promoted C−C bond formation to obtain 4,4'-bipyrazolones." Beilstein Journal of Organic Chemistry 14 (June 4, 2018): 1287–92. http://dx.doi.org/10.3762/bjoc.14.110.

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Dialkyl 5,5'-dioxo-4,4'-bipyrazole-4,4'-dicarboxylates are readily obtained by the reaction of 5-hydroxypyrazole-4-carboxylates in refluxing thionyl chloride. The obtained diesters can be transformed into the corresponding 4,4'-bipyrazoles via alkaline hydrolysis and subsequent decarboxylation. Detailed NMR spectroscopic investigations (1H, 13C, 15N) were undertaken with all products prepared. Moreover, the structure of a representative 5,5'-dioxo-4,4'-bipyrazole-4,4'-dicarboxylate was confirmed by X-ray crystal structure analysis.

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28

Elix, John A., and Judith H. Wardlaw. "The Structure of Chalybaeizanic Acid and Quaesitic Acid, Two New Lichen Depsidones Related to Salazinic Acid." Australian Journal of Chemistry 52, no. 7 (1999): 713. http://dx.doi.org/10.1071/ch99056.

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The depsidones chalybaeizanic acid (1,4,10-trihydroxy-8-methyl-3,7-dioxo-1,3-dihydro-7 H-isobenzofuro- [4,5-b][1,4]benzodioxepin-5,11-dicarbaldehyde) (4) and quaesitic acid (11-formyl-1,4,10-trihydroxy-8- methyl-3,7-dioxo-1,3-dihydro-7 H-isobenzofuro[4,5-b][1,4]benzodioxepin-5-methyl hydrogen fumarate) (5) have been isolated from the lichens Xanthoparmelia amphixanthoides and Hypotrachyna quaesita respectively, and their structures determined by a combination of spectroscopic evidence, partial synthesis, derivatization or degradation reactions.

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29

Elix, John A., Klaus Kalb, and Judith H. Wardlaw. "Neotricone and Norperistictic Acid, Two New Depsidones from the Lichen Genus Phaeographis." Australian Journal of Chemistry 56, no. 4 (2003): 315. http://dx.doi.org/10.1071/ch02194.

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Two new β-orcinol depsidones, neotricone (4,10-dihydroxy-5,8-dimethyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepin-11-carboxylic acid) (2) and norperistictic acid (1,4,10-trihydroxy-5,8-dimethyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepin-11-carboxylic acid) (4) have been identified in the lichens Phaeographis syngraphizans and P. neotricosa. The structure of the new depsidones followed from a combination of partial syntheses, chromatographic comparisons, and spectroscopic data.

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30

Peikova, Lily, Diana Tzankova, Alexandrina Dineva, Maya Georgieva, and Alexander Zlatkov. "Development of a chiral RP-HPLC method for identification of stereomers of newly synthesized xanthine-based hydrazide-hydrazone compound." Pharmacia 66, no. 1 (2019): 1–5. http://dx.doi.org/10.3897/pharmacia.66.e35643.

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A reversed phase enantio selective high performance liquid chromatographic method was developed for enantiomeric separation of 2-(1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purine-7(6H)-yl)-N'-(3-fluorobenzylidene)-propanehydrazide isomers. The enantiomers of 2-(1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purine-7(6H)-yl)-N'-(3-fluorobenzylidene)propanehydra-zide were resolved on a ACEÒEquivalenceTM С18 (250 × 4.6 mm, 5 μm) column using a mobile phase system containing methanol, water, phosphate buffer рН 7.4 (50:46:4 v/v/v). The resolution between enantiomers was found to be more than 2.0. The sample so

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31

Sah, Pramilla, Neha Saraswat, and Manu Manu. "Synthesis of Phthalyl Substituted Imidazolones and Schiff Bases as Antimicrobial Agents." E-Journal of Chemistry 8, no. 1 (2011): 427–34. http://dx.doi.org/10.1155/2011/726315.

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A new series of phthalyl substituted imidazolones (4a–g) and Schiff bases (5a–d) were synthesized from 2-methyl-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)-5-amino-1,3,4-thiadiazole (3a–b). Compounds (3a–b) were prepared by cyclisation of 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)methyl ethanoate (2) with thiosemicarbazide. 2-(m-nitro-1,3-dioxo-1,3-dihydro-(2H)-isoindole-2-yl)ethanoic acid (1) in presence of thionyl chloride and methanol gave the ester (2) while compound (1) was synthesized by aminolysis of phthalic anhydride with glycine. The compounds were characterized by

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32

Bozóová, Alena, Alfonz Rybár, Juraj Alföldi, and Gabriela Bašnáková. "3-Alkyl-6-methyl-5,7-dioxo-4,5,6,7-tetrahydro-1,2,3-triazolo[4,5-d]pyrimidines and Their Alkylations." Collection of Czechoslovak Chemical Communications 57, no. 6 (1992): 1314–25. http://dx.doi.org/10.1135/cccc19921314.

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Alkylation of 3-alkyl-6-methyl-5,7-dioxo-4,5,6,7-tetrahydro-1,2,3-triazolo[4,5-d]pyrimidines I with alkyl halides in dimethylformamide in the presence of potassium carbonate, or by analogous alkylation of sodium salts of compounds I afforded the respective 4-alkyl derivatives III but not 5-alkyloxy-3-alkyl-6-methyl-7-oxo-6,7-dihydro-1,2,3-triazolo[4,5-d]pyrimidines IV or isomeric 1,3-dialkyl-6-methyl-5,7-dioxo-4,5,6,7-tetrahydro-1,2,3-triazolo[4,5-d]pyrimidinium halides II.

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33

Jin, Ning, Mohammed Ibrahim, Thomas G. Spiro, and John T. Groves. "Trans-dioxo Manganese(V) Porphyrins." Journal of the American Chemical Society 129, no. 41 (2007): 12416–17. http://dx.doi.org/10.1021/ja0761737.

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34

Garín, Javier, Enrique Meléndez, Francisco L. Merchán, et al. "Diheterocyclic compounds from dithiocarbamates and derivatives thereof.V. 4,4′-dioxo-2,2′-dithioxo(dioxo)-6,6′-biquinazolines." Journal of Heterocyclic Chemistry 27, no. 5 (1990): 1351–54. http://dx.doi.org/10.1002/jhet.5570270532.

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35

Elix, JA, KL Gaul, PW James, and OW Purvis. "Three New Lichen Depsidones." Australian Journal of Chemistry 40, no. 2 (1987): 417. http://dx.doi.org/10.1071/ch9870417.

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The depsidones α- acetylconstictic acid (5-acetoxymethyl-1,4-dihydroxy-10-methoxy-8-methyl-3,7-dioxo-1,3-dihydro-7 H- isobenzofuro [4,5- b][l,4] benzodioxepin-ll-carbaldehyde ) (6), substictic acid (1,4-dihydroxy-10-methoxy-8-methy1-3,7-dioxo- 1,3-dihydro-7 H- isobenzofuro [4,5-b][1,4]benzodioxepin-11-carbaldehyde) (7) and conphysodalic acid (9-acetoxymethyl-3,8-dihydroxy-4-hydroxymethyl-1,6-dimethyl-11-oxo-11 H- dibenzo [ b,e ][l,4]dioxepin-7-carboxylic acid) (12) have been identified in lichens and characterized.

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36

Niopas, Ioannis, and Gordon A. Smail. "N-substituted tricyclic isoquinoline hydantoins." Collection of Czechoslovak Chemical Communications 55, no. 2 (1990): 540–45. http://dx.doi.org/10.1135/cccc19900540.

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Mannich condensation of the 1,3-dioxo-5H-10,10a-dihydroimidazo[1,5-b]isoquinoline (Ia) and 5-ethoxy-10-bromo-1,3-dioxo-5H-imidazo[1,5-b]isoquinoline (IVa) with secondary amines gave a series of N-2-aminomethyl isoquinoline hydantoins IIa-IIg and IVb, respectively. Alkylation of Ia with N,N-dialkylaminoethyl chlorides and ethyl chloroacetate afforded the N-dialkylaminoethyl and N-ethoxycarbonylmethyl derivatives Va, Vb and IIh. The N-2-hydroxymethyl and N-2-amino isoquinoline hydantoins IIj and If were also prepared.

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37

Lan, Zhenzhuo, and Shaama Mallikarjun Sharada. "Computational strategies to probe CH activation in dioxo-dicopper complexes." Physical Chemistry Chemical Physics 20, no. 40 (2018): 25602–14. http://dx.doi.org/10.1039/c8cp05096a.

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38

Boluda, Carlos José, José Piñero, Marialina Romero, et al. "Anti-leishmanial Activity of Justicidone and its Synthetic Precursors." Natural Product Communications 2, no. 2 (2007): 1934578X0700200. http://dx.doi.org/10.1177/1934578x0700200212.

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Justicidone, a C-5, C-8 dioxo-lignan of the arylnaphthalene type isolated from Justicia hyssopifolia, and its synthetic precursors were tested for the activity against Leishmania braziliensis and Leishmania amazonensis promastigotes in vitro. Justicidone showed activity against L. braziliensis with an IC50 of 181.90 μM, while, the diasteromeric mixture of one of its synthetic precursors exhibited activity against both parasite strains with an IC50 of 99.27 μM (L. braziliensis) and 181.75 μM (L. amazonensis). This activity has not previously been reported for dibenzylbutyrolactones and dioxo-li

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39

Pieper, D. H., K. Stadler-Fritzsche, H. J. Knackmuss, K. H. Engesser, N. C. Bruce, and R. B. Cain. "Purification and characterization of 4-methylmuconolactone methylisomerase, a novel enzyme of the modified 3-oxoadipate pathway in the gram-negative bacterium Alcaligenes eutrophus JMP 134." Biochemical Journal 271, no. 2 (1990): 529–34. http://dx.doi.org/10.1042/bj2710529.

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4-Carboxymethyl-4-methylbut-2-en-4-olide (4-methyl-2-enelactone) isomerase, transforming 4-methyl-2-enelactone to 3-methyl-2-enelactone, was purified from a derivative strain of Pseudomonas sp. B13, named B13 FR1, carrying the plasmid pFRC2OP. This plasmid contained the isomerase gene cloned from Alcaligenes eutrophus JMP 134, which uses 4-methyl-2-enelactone as a carbon source. The enzyme consists of a single peptide chain of Mr 40,000 as judged by SDS/PAGE. In addition to 4-methyl-2-enelactone, the putative reaction intermediate, 1-methyl-3,7-dioxo-2,6-dioxy-bicyclo[3.3.0]octane (1-methylbis

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40

Hassan, Alaa, Nasr Mohamed, Kamal El-Shaieb, Hendawy Tawfeek, Stefan Bräse, and Martin Nieger. "Eschenmoser Coupling Reaction and Reactivity of Hydrazinecarbothioamides in the Synthesis of Benzindazole and Naphthothiazole Derivatives." Synthesis 49, no. 16 (2017): 3720–25. http://dx.doi.org/10.1055/s-0036-1588179.

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N-Unsubstituted and N-substituted 2-phenylhydrazinecarbothioamides react with 2,3-dichloro-1,4-naphthoquinone to give a series of unprecedented 3-amino- and 3-(alkylamino)-1-phenyl-1H-benzo[f]indazole-4,9-diones in good yields. On the other hand, the reaction of N-substituted 2-tosylhydrazinecarbothioamides with 2,3-dichloro-1,4-naphthoquinone afforded (Z)-N-[3-(tosylamino)-4,9-dioxo-4,9-dihydronaphtho[2,3-d]thiazol-2(3H)-ylidene]-substituted aminium chlorides and (Z)-N-[(2-substituted imino)-4,9-dioxo-4,9-dihydronaphtho[2,3-d]thiazol-3(2H)-yl]-4-toluenesulfonamide hydrates.

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41

Ukrainets, Igor, Ganna Hamza, Anna Burian та ін. "Molecular Conformations and Biological Activity of N-Hetaryl(aryl)alkyl-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides". Scientia Pharmaceutica 86, № 4 (2018): 50. http://dx.doi.org/10.3390/scipharm86040050.

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The analysis of our previous studies on the search for synthetic analgesics among N-R-amides of bicyclic hetaryl-3-carboxylic acids has been performed; on its basis N-hetaryl(aryl)-alkyl-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides have been selected as new study objects. The “one pot synthesis” of these compounds, which is simple to perform and at the same time highly effective, has been offered. The method consists in the initial reaction of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and N,N′-carbonyldiimidazole in anhydrous N,N-dimethylformamide with the subsequ

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42

Gutman, Ivan. "On the oxidation of dibenzo[fg,ij]pentaphene and dinaphtho[2,1,8,7-defg:2',1',8',7'-ijkl]pentaphene dianions." Journal of the Serbian Chemical Society 64, no. 10 (1999): 563–70. http://dx.doi.org/10.2298/jsc9910563g.

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The dianion of dibenzo[fg,ij]pentaphene has recently been synthesized and shown to react with oxygen, forming the 15,16-dioxo derivative in nearly quantitative yield. Oxidation of the dianion of dinaphtho[2,1,8,7-defg:2',1',8',7'-ijkl]pentaphene under similar conditions does not result in any dioxo product. It is shown that these findings are a consequence of the different modes of cyclic conjugation in the two dianions. Cyclic conjugation in the mentioned two dianions, as well as in a number of other structurally related benzenoid dianions is assessed by means of a quantum-chemical method, de

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43

Samanta, Suman Kalyan, Eduard Preis, Christian W. Lehmann, et al. "One-step synthesis of a cyclic 2,17-dioxo[3,3](4,4′) biphenylophane and first preparation of a microporous polymer network from a macrocyclic precursor by cyclotrimerization." Chemical Communications 51, no. 43 (2015): 9046–49. http://dx.doi.org/10.1039/c5cc01654a.

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44

Saghanezhad, Seyyed Jafar, Yaser Nazari, and Fereshteh Davod. "Cucurbit[6]uril-OSO3H: a novel acidic nanocatalyst for the one-pot preparation of 14-aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes." RSC Advances 6, no. 30 (2016): 25525–30. http://dx.doi.org/10.1039/c6ra02255c.

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45

Zhang, Rui, Wen Zhou, and Jeffrey J. Warren. "Photo-initiated oxidation of C–H bonds by diimine complexes of vanadium(v)." Chemical Communications 57, no. 33 (2021): 4007–10. http://dx.doi.org/10.1039/d1cc00649e.

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46

Journal, Baghdad Science. "Hydrolysis of rhenium(v) Dioxo Complexes." Baghdad Science Journal 2, no. 2 (2005): 295–300. http://dx.doi.org/10.21123/bsj.2.2.295-300.

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47

Gutman, Ivan. "On dioxo derivatives of benzenoid hydrocarbons." Journal of Molecular Structure: THEOCHEM 460, no. 1-3 (1999): 47–51. http://dx.doi.org/10.1016/s0166-1280(98)00305-4.

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48

Legzdins, P., S. J. Rettig та S. F. Sayers. "Dioxo(η5-pentamethylcyclopentadienyl)(trimethylsilylmethyl)tungsten(VI)". Acta Crystallographica Section C Crystal Structure Communications 52, № 6 (1996): 1355–57. http://dx.doi.org/10.1107/s0108270196001217.

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49

Uerdingen, Marc, Markus Schürmann, Hans Preut, and Norbert Krause. "3,17-Dioxo-11-fluoroandrosta-4,6-diene." Acta Crystallographica Section E Structure Reports Online 57, no. 2 (2001): o106—o107. http://dx.doi.org/10.1107/s1600536801000484.

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50

Andrade, L. C. R., J. A. Paixão, M. J. de Almeida, E. J. Tavares da Silva, M. L. Sá e Melo та A. S. Campos Neves. "3,17-Dioxo-4-oxaandrostane-5α-carbaldehyde". Acta Crystallographica Section C Crystal Structure Communications 55, № 4 (1999): 637–39. http://dx.doi.org/10.1107/s0108270198015728.

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