- Unusual course of the reaction of N-(tosylmethyl)thiourea and n-(azidomethyl)thiourea with sodium enolate of dimedone
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The end product of the reaction of N-(tosylmethyl)thiourea or N-(azidomethyl)thiourea with sodium enolate of dimedone is bis(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)methane (methylenebisdimedone) instead of the expected 8a-hydroxy-7,7-dimethyl-2-thiox
- Shutalev,Kishko
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- Thermal and microwave assisted synthesis of N-aroylamino acridinediones
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A series of N-aroylamino acridinediones (3a-3d and 6a-6e) have been synthesized from tetraketones (1 and 4) and benzoic hydrazides (2a-2d and 5a-5e) under thermal and microwave irradiation conditions with solid supports.
- Josephrajan,Ramakrishnan
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- Conversion of 10-bromo-10,11-dihydrocinchonidine into 8-oxa-1-azabicyclo[4. 3.0]nonane derivatives and related compounds: A structural study
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The structure of dehydrobromination products of 10-bromo-10,11- dihydrocinchonidine 2c has been investigated in order to explore the scope of the conversions so far observed for quinine and cinchonine. The 2c rearranges into a mixture of 4(S)-(E-propenyl)-6(S),7(R)-(quinol-4-yl)-8-oxa-1(R)- azabicyclo[4.3.0]nonane 6 and its Z-propenyl diastereomer 8 in the ratio 3: 1 and also provides Z-3,10-didehydro-10,11-dihydrocinchonidine 18. The mixture of 6 and 8 undergoes catalytic hydrogenation giving 4(S)-propylo-6(S),7(R)-(quinol- 4-yl)-8-oxa-1(R)-azabicyclo[4.3.0]nonane 10. On treatment with an acid the alkaloid 6 yields [4(S)-E-propenyl-2(S)-piperidinyl]-4-quinoline α(R)-methanol 14. Its side chain undergoes hydrogenation affording 4(S)-propylo-derivative 12 which also forms on treatment of 10 by acid. The alkaloids 6, 8, 10, 12 and 14 appear as dominating conformers in their equilibrium mixtures.
- Desperak, Danuta,Paw?owski, Jacek,Thiel, Jacek
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- Selective Conversion of Carbon Dioxide to Formaldehyde via a Bis(silyl)acetal: Incorporation of Isotopically Labeled C1 Moieties Derived from Carbon Dioxide into Organic Molecules
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The conversion of carbon dioxide to formaldehyde is a transformation that is of considerable significance in view of the fact that formaldehyde is a widely used chemical, but this conversion is challenging because CO2 is resistant to chemical transformations. Therefore, we report here that formaldehyde can be readily obtained from CO2 at room temperature via the bis(silyl)acetal, H2C(OSiPh3)2. Specifically, formaldehyde is released from H2C(OSiPh3)2 upon treatment with CsF at room temperature. H2C(OSiPh3)2 thus serves as a formaldehyde surrogate and provides a means to incorporate CHx (x = 1 or 2) moieties into organic molecules. Isotopologues of H2C(OSiPh3)2 may also be synthesized, thereby providing a convenient means to use CO2 as a source of isotopic labels in organic molecules.
- Rauch, Michael,Strater, Zack,Parkin, Gerard
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supporting information
p. 17754 - 17762
(2019/11/05)
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- Merging supramolecular catalysis and aminocatalysis: Amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones
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Well-designed amino-appended β-cyclodextrins (ACDs) with an amino side chain of different lengths at the primary face of β-CD were synthesized and employed in the catalytic synthesis of a series of tetraketones as supramolecular catalysts in water for the first time. Yields of 58-97% were obtained with up to 30 examples of substrate. The catalyst could be recycled easily, while a 92% yield and 84% rate of catalyst recovery could be achieved after 8 cycles of catalyst recycling. Moreover, a catalytic mechanism merging supramolecular catalysis and aminocatalysis could be proposed through detailed 1D and 2D NMR, ESI-MS and Job plot analyses. This protocol retained the promising characteristics of ambient temperature, green medium, simple operation, broad substrate scope, excellent yields, superb catalyst recycling performance and unique catalytic mechanism.
- Ren, Yufeng,Yang, Bo,Liao, Xiali
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p. 22034 - 22042
(2016/03/08)
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- The crystal structure and conformational studies of acridinedione derivatives
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Two crystal structures of acridinediones namely, TMHAD and MPHAD were studied by X-ray crystallographic method in view of their occurrence in numerous commercial products including pharmaceuticals, fragrances and dyes. Crystal data of TMHAD are: C17H23NO2, orthorhombic, Fdd2, with cell parameters a = 40.417(6) A, b = 5.744(1) A, c = 12.979(2) A, V = 3013.1(7) A3, Z = 8, Dcal = 1.205 Mg/m3, μ = 0.078 mm-1. Crystal data of MPHAD are: C20H18NO3; monoclinic, P21/c with cell parameters a = 10.182(9) A, b = 17.105(14) A, c = 10.895(9) A, β = 117.857(1)°, V = 1678(2) A3, Z = 4, Dcal = 1.268 Mg/m3, μ = 0.085 mm-1. Both data were collected using λ (MoKα) = 0.71073 A. The central ring in the acridinedione moieties tends to be planar while the outer two rings adopt sofa conformations. Intermolecular interactions of C-H...O type of hydrogen bond help the molecules to stabilize into the crystal packing. Interestingly, a week forces of C-H...π interactions also helps the molecules for stabilization. Graphical Abstract: Two crystal structures of acridinediones namely, TMHAD and MPHAD have been synthesized and its structural chemistry has been proved by crystallographic study.
- Natarajan, Sampath,Mathews, Rita
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experimental part
p. 678 - 683
(2011/12/03)
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- A novel three-component reaction of anilines, formaldehyde and dimedone: simple synthesis of spirosubstituted piperidines
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A three-component condensation of anilines with dimedone and formaldehyde leads to the formation of 3,5-dispirosubstituted piperidines. This simple reaction can serve as a convenient source of 3,5-disubstituted piperidines as well as polyfunctional 3-spir
- Kozlov, Nikolas G.,Kadutskii, Aliaksei P.
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p. 4560 - 4562
(2008/09/21)
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- APOPTOSIS INHIBITORS
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Apoptosis inhibitors containing as the active ingredient compounds represented by general formula (I) or salts thereof, wherein W1 represents -O-, -CH2-, etc.; W2 represents -CH2-, etc.; W3 represents -O-, -CH2-, etc.; X represent CH, C-, etc.; and A represents formula (α) wherein W4 represents -O-, -CH2-, etc.; W5 represents -CH2 -, etc.; and W6 represents -O-, CH2 -, etc. These apoptosis inhibitors inhibit apoptosis of WC8 cells induced by Fas ligand. In animal models, they potently inhibit the progress of fulminant hepatitis and relieve alopecia caused by anticancer agents. Because of being highly safe, these apoptosis inhibitors are usable as beneficial drugs.
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- Synthesis, characterization, and electrochemistry of some acridine-1,8-dione dyes
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The synthesis, characterization, and electrochemical behavior of some acridinedione derivatives are reported. Cyclic voltammetric studies show that all the dyes undergo irreversible oxidation irrespective of the substitution on the nitrogen. The product formed on oxidation is the aromatic derivative in the case of N-H compounds and the acridinium salt in the case of the N-substituted compounds, which have been isolated and characterized. Formation of an intermediate carbon-centered radical is observed as evidenced by ESR spin-trapping experiments. A mechanistic scheme for the electrochemical oxidation is proposed. On carrying out reduction after oxidation, different products are formed depending on the substitution on the nitrogen. There is no reduction of the oxidized product in the case of N-H compounds, and compounds with substitution on nitrogen undergo reduction consistent with the observation in N-alkylpyridinium salts.
- Srividya,Ramamurthy,Shanmugasundaram,Ramakrishnan
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p. 5083 - 5089
(2007/10/03)
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- 3,3,6,6-tetramethyl-10-(4-methylphenyl)-3,4,6,7,9,10-hexahydro-1,8(2H,5H)- acridinedione
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The title molecule, C24H29NO2, consists of a partially hydrogenated acridine ring system with one phenyl substituent on the dihydropyridine ring. The compound crystallizes with a half molecule per asymmetric unit, which ha
- Sivaraman,Subramanian,Velmurugan,Subramanian,Shanmugasundram
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p. 481 - 483
(2007/10/03)
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- Regiospecificity and Isotope Effects Associated with the Methyl-Methylene Eliminations in the Enzyme-Catalyzed Biosynthesis of (R)- and (S)-Limonene
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-, -, and geranyldiphosphates (1-t, 1-d4, and 1-d6,t) were synthesized and used as substrates for several monoterpene cyclases to determine the regiospecificity and isotope effects attending the terminating proton transfers in the enzyme-catalyzed biosynthesis of (R)- and (S)-limonene.Degradation of enantiomeric limonenes produced by cyclization of 1-t with the (+)- and (-)-pinene cyclases (synthases) from Salvia officinalis demonstrated that the eliminations occur at both the cis- (55-65percent) and trans-methyl (45-35percent) groups.In contrast, the terminating eliminations in the formation of (+)- and (-)-limonene catalyzed by limonene cyclases from Citrus sinensis and Perilla frutescens, respectively, were shown by degradation to occur exclusively (>/=97-98percent) at the cis terminal methyl group.The intramolecular isotope effects for the methyl-methylene elimination in limonene biosynthesis catalyzed by (+)- and (-)-pinene cyclases from S. officinalis were found to be kH/kD = 2.3 +/- 0.2 and 5.9 +/- 0.5, respectively, by GC/MS determinations of -limonene derived from enzymatic cyclizations of 1-d4.Similar experiments with (-)-limonene cyclase from Mentha spicata resulted in kH/kD = 4.0 +/- 0.4.Incubations of 1-d6,t with pinene and bornyl PP cyclases from S. officinalis exhibited significant remote isotope effects (kH/kD = 1.16-1.27) on the total rate of monoterpene formation which suggest that the initial cyclization step of the enzyme-bound linalyl diphosphate intermediate is an important component of the overall rate of the enzymatic reactions.The isotope effects on the partitioning of the α-terpinyl carbocation intermediate between bicyclization and elimination to limonene were determined from the effects of deuterium substitution on the product ratios derived from enzymatic cyclization of 1-d6,t.The small size of these product isotope effects (kH/kD = 1.2-1.7) is attributed to a conformational inversion of the α-terpinyl ion to a half-chair conformer prior to proton elimination to limonene, thereby rendering the bicyclizations relatively immune to the intrinsic deuterium isotope effect.The regiospecific proton transfers from the cis terminal methyl group effected by the limonene cyclases from Citrus and Perilla are attributed to the minimization of charge seperation in the transition state.
- Pyun, Hyung-Jung,Coates, Robert M.,Wagschal, Kurt C.,McGeady, Paul,Croteau, Rodney B.
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p. 3998 - 4009
(2007/10/02)
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- A New Class of Laser Dyes from Acridinedione Derivatives
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Synthesis of 10-aryl-3,4,6,7,9,10-hexahydro-1,8(2H,5H)-acridinedione as a new class of laser dyes is reported.These dyes lase around 475-495 nm and are compared to the standard dye coumarin 102.
- Shanmugasundaram, Palanisamy,Prabahar, K. Joseph,Ramakrishnan, Vayalakkavoor T.
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p. 1003 - 1008
(2007/10/02)
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- STUDIES WITH POLYFUNCTIONALLY SUBSTITUTED HETEROCYCLES: SYNTHESIS OF NEW THIOPYRANS, PYRIDINES AND PYRANS AND THEIR FUSED DERIVATIVES WITH OTHER RINGS SYSTEMS
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The thiopyran derivative 3 was obtained from the reaction of cyanothioacetamide 2 with formaldehyde and malononitrile.Compound 3 is converted into the pyridinethione 5 on long reflux in ethanolic triethylamine solution.The pyridinethione 7 is produced from reaction of 2 with acetaldehyde and malononitrile.Compound 7 afforded 9 on reaction with 1a, R = Ph, and 11 on treatment with phenacyl bromide.The pyran derivative 13, formed in analogous manner from 12, afforded 19 on further reaction with formaldehyde and malononitrile, and 22 on reaction with acetic anhydride.Whereas the pyranopyrazole 27 is formed from 25a on reaction with formaldehyde and malononitrile in refluxing ethanol, 25b afforded only 28 an similar treatment.Similarly, thiazolopyridine derivative 30 and phthalazine 32 were formed from 29 and 31 respectively.
- Elnagdi, Mohamed Hilmy,Ghozlan, Said Ahmed Soliman,Abdelrazek, Fathy Mohamed,Selim, Maghraby Ali
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p. 1021 - 1032
(2007/10/02)
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- UREAS IN ORGANIC SYNTHESIS. VI. REACTIONS OF 1,3-DICARBONYL COMPOUNDS WITH AZOMETHINES AND UREA IN DIMETHYLSULFOXIDE AS A METHOD FOR THE SYNTHESIS OF ARYL-SUBSTITUTED ACRIDINE-1,8-DIONES AND 1,4-DIHYDROPYRIDINES
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The reactions of dimedone with urea and aromatic and alkyl aromatic azomethines in dimethyl sulfoxide, leading to the formation of hydrogenated 9-aryltetramethylacridine-1,8-diones, were investigated.It was shown that the path through the arylbisdimedonylmethane intermediate is preferred. 3,3,6,6-Tetramethyl-1,2,3,4,5,6,7,8-octahydroxanthene-1,8-dione and 9,9-dideutero derivative are formed in the reaction of DMSO and DMSO-d6 with dimedone.
- Bakibaev, A.A.,Filimonov, V.D.,Nevzgodova, E.S.
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p. 1332 - 1336
(2007/10/02)
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- FUNCTIONALISATION OF SATURATED HYDROCARBONS. PART XVII. REACTIVITY OF CARBON-CARBON DOUBLE BONDS.
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The Gif oxidation systems cleave methylidene olefins into the ketone or aldehyde and formaldehyde.This is considered to be a further manifestation of an Fe oxenoid species.Similarly, more substituted olefins are oxidized to the corresponding unsaturated ketones or aldehydes.The oxidation of limonene afforded the ketone 24 resulting from methylene cleavage and racemic carvone 25.The latter is considered to originate from a symmetrical ?-allyl complex of iron.
- Barton, Derek H. R.,Lee, Kyu Wan,Mehl, Wolf,Ozbalik, Nubar,Zhang, Li
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p. 3753 - 3768
(2007/10/02)
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- Thiamin Biosynthesis in Saccharomyces cerevisiae: Origin of the Pyrimidine Unit
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Radioactivity from 14C>formate, from D-14C>-, D-14C>-, and D-3H,6-14C>glucose, from D-14C>fructose and from 14C>- and 14C>glycerol is incorporated nonrandomly into the pyrimidine moiety of thiamin in Saccharomyces cerevisiae.The observed incorporation pattern, established by a new chemical degradation, leads to the inference that there are two biosynthetic pathways to the pyrimidine moiety of thiamin in yeast.In the major pathway, formate is the precursor of C-4 of the pyrimidine nucleus, while hexose metabolites serve as the source of the remaining five carbon atoms of the pyrimidine unit.In the minor pathway, it is C-2 and not C-4 of the pyrimidine nucleus which is derived from formate, while C-4,-5 orginates from carbohydrate.The source of C-2', C-5', and C-6 of the pyrimidine unit in this minor pathway remains unknown.Activity from 14C>citrulline and 14C>urea is not incorporated into thiamin.
- Grue-Sorensen, Gunnar,White, Robert L.,Spenser, Ian D.
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p. 146 - 158
(2007/10/02)
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- Electrophilic Substitution in Pyrroles. Part 5. Reaction of Dipyrrylmethanes with Arenediazonium Ions
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Dipyrrylmethanes react with arenediazonium ions in acid solution to form azopyrroles and formaldehyde.At low pH cleavage of the methylene bridge is brought about by attack of hydrogen ions, but at higher pH arenediazonium ions assume this role.In the reaction of benzylpyrrole, benzyl alcohol was detected as a product, suggesting formation of a benzyl carbonium ion.The relevance of these studies to the van den Bergh test for bilirubin is considered.
- Butler, Anthony R.,Shepherd, Peter T.
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p. 113 - 116
(2007/10/02)
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