- Method for synthesizing 2,7-dioxynaphthalene
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The invention relates to a method for synthesizing 2,7-dioxynaphthalene. The method comprises the following steps: adding 2,7-naphthyldisulfnate, sodium hydroxide, sodium oxide and a solvent into a high-pressure kettle; then heating to the temperature of 260-350 DEG C and carrying out stirring reaction at the temperature; cooling the obtained solution to a room temperature while stirring; after filtering, neutralizing a filter cake by using a sulfuric acid solution to PH 0-4; and filtering and drying the obtained suspension to obtain the final product. Compared with an existing method, the method uses a mixed alkali fusion reagent consisting of sodium hydroxide and sodium oxide to replace traditional independently used sodium hydroxide, the use amount of the sodium hydroxide is greatly reduced, enrichment of water in a reaction system is avoided, therefore, the generation amount of an alkali fusion by-product is reduced remarkably, and the yield of the 2,7-dioxynaphthalene is high.
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Paragraph 0009; 0021-0042
(2018/08/28)
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- Formation of Phenalenone Skeleton by an Unusual Rearrangement Reaction
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The frame rearrangement reaction of dinaphthyl ketones, possessing hydroxy groups at appropriate positions, into phenalenone derivatives under acidic conditions was discovered serendipitously. Although this rearrangement had limited scope, its mechanism was unusual, involving the division of naphthalene rings into one phenalenone ring and one benzene ring. The reaction mechanism was elucidated by direct determination of intermediate structures using 1H NMR measurements. The generated phenalenones are expected to be key intermediates toward natural products and functional materials.
- Sasaki, Sayaka,Azuma, Eriko,Sasamori, Takahiro,Tokitoh, Norihiro,Kuramochi, Kouji,Tsubaki, Kazunori
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supporting information
p. 4846 - 4849
(2017/09/23)
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- Reductive cleavage of aryl O-carbamates to phenols by the Schwartz reagent. Expedient link to the directed ortho metalation strategy?
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A general, mild, and efficient method for the reductive cleavage of aryl O-carbamates to phenols, 1 → 2 using the Schwartz reagent is reported. The method is selective, tolerating a large number of functional groups; may be carried out by direct or by an economical in situ procedure; and, notably, establishes a synthetic connection to the directed ortho metalation strategy (Figure 1) allowing new entries into difficult to prepare contiguously substituted aromatics and heteroaromatics.
- Morin, Justin,Zhao, Yigang,Snieckus, Victor
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supporting information
p. 4102 - 4105
(2013/09/12)
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- Exhaustive syntheses of naphthofluoresceins and their functions
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Naphthofluorescein and/or seminaphthofluorescein derivatives possessing the additional benzene units to one or both sides of fluorescein were exhaustively constructed through Friedel-Crafts type reactions between corresponding aroylbenzoic acids and dihydroxynaphthalenes. Compound 4 works as a one-dye pH indicator, which shows red in strong acid condition and blue in basic solution. Compound 23 (diacetate of compound 4) shows good transitivity to the HEK 293 cells and acts as a fluorescent pigment for the living cell imaging. Compounds 5, 6, and 9 show fluorescent emission in the NIR region (>700 nm) and imply the potentialities of NIR fluorescent probes.
- Azuma, Eriko,Nakamura, Naoko,Kuramochi, Kouji,Sasamori, Takahiro,Tokitoh, Norihiro,Sagami, Ikuko,Tsubaki, Kazunori
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experimental part
p. 3492 - 3500
(2012/05/20)
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- Highly efficient and scalable process for demethylation of 6-(2,4-dimethoxybenzoyl)chromen-2-one and other aryl methyl ethers
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Demethylation of 6-(2,4-dimethoxybenzoyl)chromen-2-one and some other aryl methyl ethers was achieved with pyridinium bromide as demethylating agent and sulfolane as solvent. Compared with other demethylation methods, this combination offers advantages of clean conversion, excellent yields, easy operation and workup, and manageable reaction temperatures. This process could be particularly useful for large-scale production because it avoids use of corrosive or moisture-sensitive reagents. Copyright
- Srivastava, Amit,Yang, Jason,Zhao, Baoshu,Jiang, Yong,Blackmon, Wade,Kraemer, Bernd
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experimental part
p. 1765 - 1771
(2010/07/07)
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- Synthesis of naphthalenediols by aerobic oxidation of diisopropylnaphthalenes catalyzed by N-hydroxyphthalimide (NHPI)/α, α′-azobisisobutyronitrile (AIBN)
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Naphthalenediols were successfully synthesized in a one-pot reaction through the oxidation of diisopropylnaphthalenes with air catalyzed by N-hydroxyphthalimide (NHPI) combined with α,α′- azobisisobutyronitrile (AIBN) followed by decomposition with sulfuric acid. Thus, the oxidation of 2,6-diisopropylnaphthalene with air (20 atm) in the presence of AIBN (3 mol %) and NHPI (10 mol %) in CH3CN at 75°C for 21 h followed by treatment with 0.3 M H2SO4 gave 2,6-naphthalenediol in 92% yield.
- Aoki, Yasuhiro,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 199 - 202
(2007/10/03)
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- Process for functionalising a phenolic compound carrying an electron-donating group
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The invention concerns a method for functionalizing a phenolic compound bearing an electron-donor group, in said group para position, inter alia a method for the amidoalkylation of a phenolic compound bearing an electron-donor group, and more particularly, a phenolic compound bearing an electron-donor group preferably, in the hydroxyl group ortho position. The method for functionalizing in para position with respect to an electron-donor group carried by a phenolic compound is characterised in that the phenolic compound bearing an electron-donor group is subjected to the following steps: a first step which consists of protecting the hydroxyl group in the form of a sulphonic ester function; a second step which consists in reacting the protected phenolic compound with an electrophilic reagent; optionally, a third step deprotecting the hydroxyl group.
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- Recognition of dihydroxynaphthalenes by a C2-symmetric host
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A functionalized C2-symmetric host (2) shows high affinity and substrate selectivity for dihydroxynaphthalenes.
- Kim, Hae-Jo,Moon, Dohyun,Lah, Myoung Soo,Hong, Jong-In
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p. 1887 - 1890
(2007/10/03)
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- Polymer electrolyte and process for producing the same
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A polymer electrolyte having, in a main chain, a structural unit represented by the following formula (1):-[Ar1-(SO2-N-(X+)-SO2-Ar2)m-SO2-N-(X+)-SO2-Ar1-O]- wherein Ar1 and Ar2 independently represent a divalent aromatic groups, m represents an integer of 0 to 3, and X+ represents an ion selected from hydrogen ion, an alkali metal ion and ammonium ion, which is excellent in proton conductivity, thermal resistance and strength. The polymer electrolyte is soluble in solvents and has excellent film forming property and recycling efficiency.
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- Regioselective hydrolysis of diacetoxynaphthalenes catalyzed by Pseudomonas sp. lipase in an organic solvent
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Depending on the relative positions of the acetyl groups in the aromatic rings, the Pseudomonas sp. lipase-catalyzed hydrolysis of diacetoxynaphthalenes in tert-butylmethyl ether proceeds regioselectively to afford the corresponding monoacetates.
- Ciuffreda, Pierangela,Casati, Silvana,Santaniello, Enzo
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p. 317 - 321
(2007/10/03)
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- An Investigation on Desilylation of Alkyl and Phenolic Silyl Ethers Using FeCl3
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A variety of alkyl and phenolic TBDMS ethers have been efficiently cleaved using anhydrous FeCl3 in MeOH under mild conditions. It was found that choice of solvent is crucial for the rate of the deprotection of TBDMS ether with FeCl3.
- Saravanan, Parthasarathy,Singh, Vinod K.
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p. 565 - 567
(2007/10/03)
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- New Cyclophanes as Initiator Cores for the Construction of Dendritic Receptors: Host-Guest Complexation in Aqueous Solutions and Structures of Solid-State Inclusion Compounds
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Cyclophanes 3 and 4 were prepared as initiator cores for the construction of dendrophanes (dendritic cyclophanes) 1 and 2, respectively, which mimic recognition sites buried in globular proteins. The tetraoxy[6.1.6.1]paracyclophane 3 was prepared by a short three-step route (Scheme 1) and possesses a cavity binding site shaped by two diphenylmethane units suitable for the inclusion of flat aromatic substrates such as benzene and naphthalene derivatives as was shown by 1H-NMR binding titrations in basic D2O phosphate buffer (Table 1). The larger cyclophane 4, shaped by two wider naphthyl(phenyl)methane spacers, was prepared in a longer, ten-step synthesis (Scheme 2) which included as a key intermediate the tetrabromocyclophane 5. 1H-NMR Binding studies in basic borate buffer in D2O/CD3OD demonstrated that 4 is an efficient steroid receptor. In a series of steroids (Table 1), complexation strength decreased with increasing substrate polarity and increasing number of polar substituents; in addition, electrostatic repulsion between carboxylate residues of host and guest also affected the binding affinity strongly. The conformationally flexible tetrabromocyclophane 5 displayed a pronounced tendency to form solid-state inclusion compounds of defined stoichiometry, which were analyzed by X-ray crystallography (Fig. 2). 1,2-Dichloroethane formed a cavity inclusion complex 5a with 1:1 stoichiometry, while in the 1:3 inclusion compound Sb with benzene, one guest is fully buried in the macrocyclic cavity and two others are positioned in channels between the cyclophanes in the crystal lattice. In the 1:2 inclusion compound 5c, two toluene molecules penetrate with their aromatic rings the macrocyclic cavity from opposite sides in an antiparallel fashion. On the other hand, p-xylene (= 1,4-dimethylbenzene) in the 1:1 compound 5d is sandwiched between the cyclophane molecules with its two Me groups penetrating the cavities of the two macrocycles. In the 1:2 inclusion compound 5e with tetralin (= 1,2,3,4-tetrahydronaphthalene), both host and guest are statically disordered. The shape of the macrocycle in 5a-e depends strongly on the nature of the guest (Fig. 4). Characteristic for these compounds is the pronounced tendency of 5 to undergo regular stacking and to form channels for guest inclusion; these channels can infinitely extend across the macrocyclic cavities (Fig. 6) or in the crystal lattice between neighboring cyclophane stacks (Fig. 5). Also, the crystal lattice of 5c displays a remarkable zig-zag pattern of short Br ... O contacts between neighboring macrocycles (Fig. 7).
- Wallimann, Peter,Mattei, Sebastiane,Seiler, Paul,Diederich, Francois
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p. 2368 - 2390
(2007/10/03)
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- Dendrophanes: Water-Soluble Dendritic Receptors as Models for Buried Recognition Sites in Globular Proteins
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Water-soluble dendritic cyclophanes (dendrophanes) of first (1, 4), second (2, 5), and third generation (3, 6) with poly(ether amide) branching and 12, 36, and 108 terminal carboxylate groups, respectively, were prepared by divergent synthesis, and their molecular recognition properties in aqueous solutions were investigated. Dendrophanes 1-3 incorporate as the initiator core a tetraoxa[6.1.6.1]paracyclophane 7 with a suitably sized cavity for inclusion complexation of benzene or naphthalene derivatives. The initiator core in 4-6 is the [6.1.6.1]cyclophane 8 shaped by two naphthyl(phenyl)methane units with a cavity suitable for steroid incorporation. The syntheses of 1-6 involved sequential peptide coupling to monomer 9, followed by ester hydrolysis (Schemes 1 and 4). Purification by gel-permeation chromatography (GPC; Fig. 3) and full spectral characterization were accomplished at the stage of the intermediate poly(methyl carboxylates) 10-12 and 23-25, respectively. The third-generation 108-ester 25 was also independently prepared by a semi-convergent synthetic strategy, starting from 4 (Scheme 5). All dendrophanes with terminal ester groups were obtained in pure form according to the 13C-NMR spectral criterion (Figs, 1 and 5). The MALDI-TOF mass spectra of the third-generation derivative 25 (mol. wt. 19328 D) displayed the molecular ion as base peak, accompanied by a series of ions [M - n(1041 ± 7)]+, tentatively assigned as characteristic fragment ions of the poly(ether amide) cascade. A similar fragmentation pattern was also observed in the spectra of other higher-generation poly(ether amide) dendrimers. Attempts to prepare monodisperse fourth-generation dendrophanes by divergent synthesis failed. 1H-NMR and fluorescence binding titrations in basic aqueous buffer solutions showed that dendrophanes 1-3 complexed benzene and naphthalene derivatives, whereas 4-6 bound the steroid testosterone. Complexation occurred exclusively at the cavity-binding site of the central cyclophane core rather than in fluctuating voids in the dendritic branches, and the association strength was similar to that of the complexes formed by the initiator cores 7 and 8, respectively (Tables 1 and 3). Fluorescence titrations with 6-(p-toluidino)naphthalene-2-sulfonate as fluorescent probe in aqueous buffer showed that the micropolarity at the cyclophane core in dendrophanes 1-3 becomes increasingly reduced with increasing size and density of the dendritic superstructure; the polarity at the core of the third-generation compound 3 is similar to that of EtOH (Table 2). Host-guest exchange kinetics were remarkably fast and, except for receptor 3, the stabilities of all dendrophane complexes could be evaluated by 1H-NMR titrations. The rapid complexation-decomplexation kinetics are explained by the specific attachment of the dendritic wedges to large, nanometer-sized cyclophane initiator cores, which generates apertures in the surrounding dendritic superstructure.
- Mattei, Sebastiane,Wallimann, Peter,Kenda, Benoit,Amrein, Walter,Diederich, Francois
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p. 2391 - 2417
(2007/10/03)
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- Para-hydroxyalkylation of hydroxylated aromatic compounds
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Hydroxylated aromatic compounds devoid of substituents in the para-position to the hydroxyl group thereof are para-hydroxyalkylated, e.g., into optionally substituted p-hydroxymandelic acid compounds, more particularly p-hydroxymandelic acid and 3-methoxy-p-hydroxymandelic acid, by condensing same with an organic carbonyl compound in the presence of a quaternary ammonium hydroxide.
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- SELECTIVE MONO- OR DIMETALATION OF ARENES BY MEANS OF SUPERBASIC REAGENTS
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If employed in tetrahydrofuran, stoichiometric amounts of butyllithium and potassium tert-butoxide react with benzene under clean monometalation.In hexane suspension, however, considerable amounts of meta- and para-disubstituted by-products are obtained (approx. 10percent).They become preponderant if a three-fold excess of the metalating agent is used.Naphthalene leads under the same conditions to a mixture of two mono- and ten di-substituted derivatives. - Alkyl groups, as present in tert-butylbenzene, retard the metalation at both m- and p-positions, while trialkylsilyl groups deactivate only m-position.In either case exclusive monosubstitution occurs. - Perdeuterobenzene undergoes metalation and subsequent electrophilic mono- or disubstitution to afford isotope labeled compounds with moderate, though synthetically attractive yields.The kinetic isotope effects and product ratios can be taken as evidence for aggregate formation at the level of both the superbasic metalating reagent and the organometallic intermediates.
- Schlosser, Manfred,Choi, Jung Hoon,Takagishi, Sadahito
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p. 5633 - 5648
(2007/10/02)
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- HYDROXYLATION DES NAPHTOLS EN MILIEU SUPERACIDE
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Hydroxylation of α and β naphtols by hydrogen peroxide in SbF5-HF occurs selectively on the non-phenolic ring, the electrophile reacting on the C-protonated substrate.
- Jacquesy, Jean-Claude,Jouannetaud, Marie-Paule,Morellet, Guy
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p. 3099 - 3102
(2007/10/02)
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- New Routes to Phenalenones from 2,7-Dihydroxynaphthalene. X-Ray Crystal Structure of 4-(α-Hydroxybenzyl)-2-phenyl-6H-phenaleno-pyran-6-one
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9-Aryl-6-hydroxy-1H-phenalen-1-ones and 2-aryl-4-aroyl-6H-phenalenopyran-6-ones can be obtained by the reaction of 2,7-dihydroxyphenalene-1-carbaldehyde with acetophenones and by condensation of aroylacetaldehydes with 2,7-dihydroxynaphthalene under acid conditions.Aroylacetaldehydes may be involved in the former reaction also, arising by transfer of the formyl group from the naphthaldehyde to the acetophenone. 2,7-Dihydroxynaphthalene-1-carbaldehyde reacts with 2-hydroxyacetophenone to form 1H-naphthoxanthen-1-one.Interaction of naphthalene-2,7-dioxybismagnesium dibromide with cinnamaldehydes affords 4-benzyl-2-phenyl-6H-phenalenopyran-6-ones.
- Carey, John L.,Thomson, Ronald H.,Cox, Philip J.
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p. 1267 - 1274
(2007/10/02)
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- Method for preparing adduct of butadiene polymer or copolymer and α, β-ethylenically unsaturated dicarboxylic acid compound
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In a method for preparing an adduct of (A) a butadiene lower polymer or butadiene lower copolymer and (B) a α,β-ethylenically unsaturated dicarboxylic acid compound, said method is characterized in that said (A) and (B) are caused to react in the presence of one or more compounds selected from (C) p-phenylenediamine derivatives, catechol derivatives, pyrogallol derivatives, N-nitrosamines, quinoline derivatives and naphthol derivatives, thus serious increase of the viscosity of said adduct in the addition reaction can be prevented.
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