- Studies on the synthesis of novel chiral naphthylene bisoxazoline ligands
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The synthesis of chiral C2-symmetric substituted bisoxazoline ligands containing naphthalene group were investigated. Ethyl 2,3-naphthylene-dicarboxylate reacted with amino alcohols and the resulting amides were treated with SOCl2 and then reacted with Et3N in toluene to afford the desired bisoxazolines. 2,3-Naphthylenedicarbonitrile reacted with amino alcohol give N-(1′-phenyl-2′-hydroxyethyl)-2,3naphthylenedicarboximide 1. The 2,3-naphthylenedicarboxylic acid reacted with thionyl chloride give the 2,3-Naphthalenedicarboxylic acid cyclic anhydride rather than corresponding 2,3-naphthalenedicarboxylic acid dichloride, the former reacted with amino alcohol also give compound 1. The later two strategies cannot give the target bisoxazoline.
- Wang, Zhan-Yue,Du, Da-Ming,Wu, Di,Hua, Wen-Ting
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Read Online
- Picomole scale stereochemical analysis of sphingosines and dihydrosphingosines
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We have developed a simple picomole (low nanogram) scale HPLC scheme which can separate all eight isomers of sphingosine and dihydrosphingosine thus leading to the identification of their relative and absolute configurations. The amino group of the sample is derivatized to its fluorescent N-naphthimide which is analyzed by normal and chiral phase HPLC, coupled with fluorescence peak detection. If necessary, the results of this HPLC method can be further corroborated by measurements of circular dichroic (CD) spectra of the N-naphthimido-derivatives and/or N,O-chromophoric derivatives.
- Kawamura, Akira,Berova, Nina,Dirsch, Verena,Mangoni, Alfonso,Nakanishi, Koji,Schwartz, Gary,Bielawska, Alicja,Hannun, Yusuf,Kitagawa, Isao
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Read Online
- TBHP/ n -Bu 4 PBr-Promoted Oxidative Cross-Dehydrogenative Coupling of Aryl Methanols: A Facile Synthesis of Symmetrical Carboxylic Anhydride Derivatives
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A transition-metal-free oxidative cross-dehydrogenative coupling reaction has been developed for the preparation of symmetrical carboxylic anhydrides through self-coupling dual C-O bond formations of aryl methanols. In the presence of a catalytic amount of tetrabutylphosphonium bromide (TBPB) as transfer agent and aqueous tert -butyl hydroperoxide (TBHP) as oxidant and reactant, methylene groups of aryl methanols were efficiently oxidized to C=O and coupled with the peroxide oxygen from TBHP to form a diverse array of symmetrical carboxylic anhydride derivatives.
- Adib, Mehdi,Pashazadeh, Rahim
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supporting information
p. 136 - 140
(2017/12/27)
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- Preparation method of 2,3-naphthalic acid
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The invention discloses a preparation method of 2,3-naphthalic acid, belonging to the technical field of preparation of organic compounds used as medical and liquid crystal intermediates. According to the preparation method, o-phthalaldehyde is used as a raw material, and through performing acetalation reaction, reducing reaction, hydrolysis reaction, cycloaddition reaction, dehydration reaction and hydrolysis reaction in sequence, finally the 2,3-naphthalic acid is prepared. The preparation method optimizes the reaction steps and conditions and has the advantages of reasonable synthetic route, high purity and yield of product, low production cost, low pollution, easy industrialization and the like.
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Paragraph 0055; 0062
(2017/07/23)
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- Heptacene: Characterization in Solution, in the Solid State, and in Films
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Acenes comprise an important class of organic semiconducting materials. As graphene nanoribbons of ultimate width, they are valuable atom-precise model systems for studying the properties of this form of nanoscale carbon materials. Heptacene is the smallest member of the acene series that could only be studied under matrix isolation conditions. Its existence in bulk had never been positively confirmed, despite efforts dating back more than 70 years. We report that the reduction of 7,16-heptacenequinone produces a mixture of two diheptacene molecules. The diheptacenes undergo thermal cleavage to heptacene at high temperatures in the solid state. Monitoring this cycloreversion by solid state 13C cross-polarized magic angle spinning NMR reveals that solid heptacene has a half-life time of several weeks at room temperature. The diheptacenes are valuable precursors for generating films of heptacene by vapor phase deposition that can be studied below or at room temperature.
- Einholz, Ralf,Fang, Treliant,Berger, Robert,Grüninger, Peter,Früh, Andreas,Chassé, Thomas,Fink, Reinhold F.,Bettinger, Holger F.
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supporting information
p. 4435 - 4442
(2017/04/03)
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- METHOD FOR PRODUCING CARBOXYLIC ACID ANHYDRIDE, METHOD FOR PRODUCING CARBOXYLIC IMIDE, AND METHOD FOR MANUFACTURING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER
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A method for producing a carboxylic acid anhydride includes heating a composition containing a specific compound in a solvent to yield the carboxylic acid anhydride. The solvent is an aprotic polar solvent having a boiling point of 50° C. or more.
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Paragraph 0122
(2017/01/19)
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- Facile Sc(OTf)3-catalyzed generation and successive aromatization of isobenzofuran from o -dicarbonylbenzenes
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Isobenzofuran can be prepared from o-phthalaldehyde using hydrosilane. The formed isobenzofuran is trapped by an alkene via a Diels-Alder reaction. Further dehydration proceeds to furnish the conjugated aromatic compound. This multistep reaction was promoted by catalytic amounts of Sc(OTf)3.
- Nishina, Yuta,Kida, Tatsuya,Ureshino, Tomonari
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supporting information; experimental part
p. 3960 - 3963
(2011/10/01)
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- New efficient route to fused aryltetrahydroindolizinones via N-Acyliminium intermediates
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Straightforward routes to fused tetrahydroindolizinones by two routes A and B, starting either from. 2-formylbenzoic acid and esters or from, β-hydroxy lactones via acyl iminium ions, are described. A plausible mechanism and limitations are given. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009.
- Chiurato, Matteo,Routier, Sylvain,Troin, Yves,Guillaumet, Gerald
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scheme or table
p. 3011 - 3021
(2009/11/30)
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- Discovering a new analogue of thalidomide which may be used as a potent modulator of TNF-α production
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A new series of imide derivatives related to thalidomide were synthesized and evaluated as modulators of TNF-α production. These derivatives enhance TNF-α production using human leukemia HL-60 cells induced with 12-O-tetradecanoylphorbol 13-acetate (TPA), while inhibiting TNF-α production induced with okadaic acid (OA) in the same cell line. The diphenylmaleimide derivative 2f, was found to be the most active product, producing a strong modulation of the cytokine level.
- Brana, Miguel Fernandez,Acero, Nuria,Anorbe, Loreto,Mingarro, Dolores Munoz,Llinares, Francisco,Dominguez, Gema
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body text
p. 3533 - 3542
(2009/12/04)
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- Synthesis and photophysical properties of dihydroheptacenes: New blue-emitting materials
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7,16-Dihydroheptacenes (1-3) substituted at the 6, 8, 15, and 17 positions are synthesized as blue emitters potentially useful in organic light emitting diodes (OLEDs). The photophysical properties of 1-3 (λmax = 424-428 nm, ΦF = 0.15-0.21, τF = 2.35-2.67 ns in CH2Cl2) are discussed. They are shown to be stable and efficient blue emitters in the solid state (ΦF = 0.37-0.44). The X-ray crystal structure of 1 is reported.
- Mondal, Rajib,Shah, Bipin K.,Neckers, Douglas C.
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p. 4085 - 4091
(2007/10/03)
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- THALIDOMIDE ANALOGS
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Thalidomide analogs that modulate tumor necrosis factor alpha (TNF-α) activity and angiogenesis are disclosed. In particularly disclosed embodiments, the thalidomide analogs are isosteric sulfur-containing analogs. Also disclosed are methods of treating a subject with the analogs.
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Page/Page column 36-37
(2008/06/13)
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- Synthesis and characterization of coronanes: Multicyclopropane-fused macrocyclic arrays
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Stepwise macrocyclization of the all syn-trans-1,15-quinquecyclopropanedimethanol (4) with isoand terephthaloyl chlorides and 4,4′-methanediyl-dibenzoic acid (28) gave the corresponding coronanes 22, 23, and 32. The same protocol was used with all syn-trans-1,21-septecyclopropanedimethanol (5) and 2,3-naphthalenedicarboxylic acid to obtain the macrolide 27. Direct macrocyclization of diol 4 and 1,10-phenanthroline-2,9-dicarbonyl chloride (33) and 2,2′-bipyridine-4,4′-dicarbonyl chloride (35) gave the coronanes 34 and 36, respectively. Ring closing metathesis (RCM) of the diene 42 using Cl2(Cy3P)2Ru=CHPh (48) (Grubbs's catalyst) gave the macrocyclic lactone 45. The structures of coronanes 22, 23, 32, 34, 36, and 45 were confirmed by X-ray crystallographic studies which showed the cyclopropyl chain to adopt very differing conformations throughout the series. Several of the macrocycles have significant free pathways through their ring centers, and in the case of compound 34 there is a water molecule hydrogen bonded within the ring. This latter compound has the potential to act as a chiral ligand to metal centers.
- Barrett,Hamprecht,James,Ohkubo,Procopiou,Toledo,White,Williams
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p. 2187 - 2196
(2007/10/03)
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- Products of benz[a]anthracene photodegradation in the presence of known organic constituents of atmospheric aerosols
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Products of benz[a]anthracene photodegradation were determined after irradiation of benz[a]anthracene in the presence of three common constituents of atmopsheric aerosols previously found to accelerate benz[a]anthracene photodegradation; 9,10-anthraquinone, 9-xanthone, and vanillin. Among the major tentatively identified products were benz[a]anthracene-7, 12-dione, phthalic acid, phthalic anhydride, and 1,2-benzenedicarboxaldehyde. Evidence for production of polycyclic dicarboxylic acids and dialdehydes was also obtained. Product distribution was strongly influenced by solvent effects and dissolved aerosol constituents. The results suggest that products of PAH photodegradation in atmospheric aerosols are likely to be quite complex and strongly influenced by the organic composition of PAH-containing aerosol particles.
- Myoseon Jang,McDow
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p. 1046 - 1053
(2007/10/03)
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- Chromophore-modified antitumor anthracenediones: Synthesis, DNA binding, and cytotoxic activity of 1,4-bis[(aminoalkyl)amino]benzo[g]-phthalazine- 5,10-diones
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As part of a program aimed at exploring the effect of the introduction of heteroatoms into the anthracene-9,10-dione chromophore, we have synthesized novel 1,4-bis[(aminoalkyl)amino]-benzo[g]phthalazine-5,10-diones (BPDs) 1 which are related to the antitumor agents ametantrone and mitoxantrone. Derivatives 1 were prepared by chromic acid oxidation of acylated benzo[g]phthalazines 5 followed by acid hydrolysis or by silylation-amination of 5,10-dihydroxybenzo[g]phthalazine-1,4-dione (8). The 1- [(aminoalky])amino]-4-amino congeners 2 were isolated in low yields as byproducts from the oxidation of 5. Against a panel of human tumor cell lines, the benzo[g]phthalazine-5,10-diones 1 and 2 exhibited cytotoxic activity comparable or even superior to that of mitoxantrone. In compounds 1, structure activity relationships different than those operative in the carbocyclic series appeared to emerge. DNA-binding studies with the ametantrone-like compound 1c and its single-armed congener 2c indicated that the introduction of a 2,3-diaza subunit into the anthracene-9,10-dione chromophore reduces the affinity of the drug for DNA in comparison with ametantrone. On the other hand, the number of side-chain groups does not affect binding to a great extent. These findings seem to suggest mechanisms of cell death other than those induced by simple interaction of the 1,4-BPDs 1 and 2 with DNA.
- Gandolfi,Beggiolin,Menta,Palumbo,Sissi,Spinelli,Johnson
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p. 526 - 536
(2007/10/02)
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- Stabilization energy of polyenyl radicals: All-trans-nonatetraenyl radical by thermal rearrangement of a semirigid {4-1-2} heptaene. Model for thermal lability of β-carotene
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Evaluation of the stabilization energy of the nonatetraenyl radical directly from the enthalpy of activation of the thermal anti-syn rearrangement of a semirigid nonaene having a symmetrical distribution {4-1-4} of double bonds is thwarted by insolubility. Indirect comparison of the enthalpy of activation of an asymmetrical {4-1-2} heptaene with that of an already determined symmetrical {2-l-2} pentaene leads to an inferred enthalpy of activation of 24.5 kcal/mol for the {4-1-4} nonaene. Perhaps the point of greatest theoretical interest is the rapidity with which successive increments in stabilization energies (SEn) decrease with increasing number of double bonds in the conjugated polyenyl radicals. Values of SEn for n = 1 (allyl), 2 (pentadienyl), 3 (heptatrienyl), and 4 (nonatetraenyl) are 13.5, 16.9, 19.2, and 20.7 kcal/mol, respectively.
- Doering, W. Von E.,Sarma, Keshab
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p. 6037 - 6043
(2007/10/02)
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- 1,4-bis(alkylamino)-2,3-diaza-anthracene-9,10-diones
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Compounds of formula I are described, STR1 wherein: R1 and R2, that can be the same or different, are hydrogen or acyl groups; R3 and R4, that can be the same or different, are hydrogen or optionally substituted alkyl groups. The compounds of formula I are prepared by oxydation of the compounds of formula II: STR2 wherein the groups R'1, R'2, R'3 and R'4 have the same meanings as R1, R2, R3 and R4 or groups convertible to the latter. The compounds of formula I have remarkable antitumor activity.
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- Photochemical Reactions of N-Methylnaphthalene-2,3-dicarboximide with Alkenes
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Previous studies have been shown that N-methylphthalimide (NMP) reacts with alkenes to afford, in a few cases, oxetanes, along with products of alkene addition to the C(O)N bond and products arising from initial electron transfer.In this paper we explore the photochemistry of N-methylnaphthalene-2,3-dicarboximide (NMN).The photochemistry of NMN was studied in benzene, a solvent which we were unable to use with NMP due to solubility factors.In this solvent oxetanes were the major products found with several alkenes (α-methylstyrene, diphenylethylene, styrene, trans-stilbene).In the case of trans-stilbene a novel 2 + 2 addition to the 1,2-bond of NMN was also observed to give a photochemically labile cyclobutane.In benzene solvent alkene addition to the C(O)N bond was never a major product.Also investigated was a series of alkenes in acetonitrile containing methanol in which the expected products obtained by trapping the electron-transfer-generated radical anion radical cation pair with methanol were found.In the case of 2,3-dimethyl-2-butene there was observed a pair of photoreduction products analogous to those observed with this alkene and NMP.A study of solvent polarity effects on the ratio of these photoreduction products supports the previous suggestion that one of these arises via proton transfer followed by coupling of the radical pair, whereas the other comes from a rare case of radical cation-radical anion coupling followed by intramolecular proton transfer in the resultant zwitterion.Fluorescence quenching data for NMN with a series of unsaturated hydrocarbons are presented, and these data are shown to correlate well with the Weller equation.
- Kubo, Yasuo,Suto, Manami,Araki, Takeo,Mazzocchi, Paul H.,Klingler, Lori,et al.
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p. 4404 - 4411
(2007/10/02)
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- AMINOPHTHALAZINONE DERIVATIVES, VI; SYNTHESIS OF 4-(HYDROXYALKYLAMINO)-BENZO-1(2H)-PHTHALAZINONES
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The methods developed from procedures published earlier make possible the synthesis of various 4-(alkylamino-benzo-1(2H)-phthalazinones.Method A (1-->6, 7) is suitable for the incorporation of 1,2- or 1,3-aminoalcohols.When starting from N-β-tosyloxyalkylnaphthalene-2,3-dicarboxylic imides (2; M: -) and 3-bromo-propylimides (3b), parent compounds 6 and the compounds containing methyl, 2-hydroxyethyl and 2-diethylaminoethyl substituents at the N(2) position (7) are formed in excellent and medium yield, respectively.A greater variety of derivatives can be synthesized by Method B, since coupling of 4-chlorobenzo-1(2H)-phthalazinone (9) with aminoalcohols (9-->6a, 6f, 11, 12) is independent of the relative distance between the amino and hydroxy terminals, and the N-substitution (9-->13, 14) of hydroxy-free primary and secondary amines can also be achieved in ethylene glycol solutions.
- Koermendy, K.,Ruff, F.
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p. 175 - 188
(2007/10/02)
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- Benzocyclobutenes. Part 4. Synthesis of Benzocyclobutene-1,2-diones by Pyrolytic Methods
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Oxidation of the cyclic hydrazides prepared from phthalic anhydrides in the presence of anthracene gives the corresponding Diels-Alder adducts which, on flash vacuum pyrolysis, give benzocyclobutene-1,2-dione (BBD) and its 4-chloro, 3,6- and 4,5-dichloro, 4,5-dibromo, and 4,5-dimethyl derivatives in 75-98percent yield.Cyclobuta- and cyclobuta-naphthalene-1,2-dione as well as cyclobuta- and cyclobuta-pyridine-1,2-dione have been prepared similarly; the last three of these diones are very unstable.Cyclobutanaphthalene-1,2-dione has also been made by pyrolysis of benzindene-1,2,3-trione.Attempts to make thiophen and furan analogues of BBD from appropriate anthracene adducts failed as did attempts to make tetrachloro- and tetrabromo-derivatives of BBD by the pyrolysis of tetrahalogenophthalimidosulphoximides.
- Gould, Ken J.,Hacker, Nigel P.,McOmie, John F. W.,Perry, David H.
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p. 1834 - 1840
(2007/10/02)
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