- Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: Toward the emergence of new building blocks
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4-Methoxy-ortho-phthalaldehyde and 4-hydroxy-ortho-phthalaldehyde are potentially useful molecules for fluorimetric analysis of a variety of amines and for the elaboration of complex molecular architectures. Nevertheless, literature generally describes their synthesis in very low yield (below 5%), mainly due to the inefficiency of the last oxidation step. In this paper, we report a reliable synthesis of 4-substituted-ortho-phthalaldehyde analogues in 51% overall yield owing to the addition of a protecting step of the unstable key intermediate 4,5-dihydroisobenzofuran-5-ol. Oxidation and deprotection steps were also studied in order to provide an effective availability of these two dialdehyde compounds that may increase their future applications.
- Moitessier, Clémence,Rifai, Ahmad,Danjou, Pierre-Edouard,Mallard, Isabelle,Cazier-Dennin, Francine
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p. 721 - 726
(2019/04/17)
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- Automated on-line monitoring of the TiO2-based photocatalytic degradation of dimethyl phthalate and diethyl phthalate
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A fully automated on-line system for monitoring the TiO2-based photocatalytic degradation of dimethyl phthalate (DMP) and diethyl phthalate (DEP) using sequential injection analysis (SIA) coupled to liquid chromatography (LC) with UV detection was proposed. The effects of the type of catalyst (sol-gel, Degussa P25 and Hombikat), the amount of catalyst (0.5, 1.0 and 1.5 g L-1), and the solution pH (4, 7 and 10) were evaluated through a three-level fractional factorial design (FFD) to verify the influence of the factors on the response variable (degradation efficiency, %). As a result of FFD evaluation, the main factor that influences the process is the type of catalyst. Degradation percentages close to 100% under UV-vis radiation were reached using the two commercial TiO2 materials, which present mixed phases (anatase/rutile), Degussa P25 (82%/18%) and Hombikat (76%/24%). 60% degradation was obtained using the laboratory-made pure anatase crystalline TiO2 phase. The pH and amount of catalyst showed minimum significant effect on the degradation efficiencies of DMP and DEP. Greater degradation efficiency was achieved using Degussa P25 at pH 10 with 1.5 g L-1 catalyst dosage. Under these conditions, complete degradation and 92% mineralization were achieved after 300 min of reaction. Additionally, a drastic decrease in the concentration of BOD5 and COD was observed, which results in significant enhancement of their biodegradability obtaining a BOD5/COD index of 0.66 after the photocatalytic treatment. The main intermediate products found were dimethyl 4-hydroxyphthalate, 4-hydroxy-diethyl phthalate, phthalic acid and phthalic anhydride indicating that the photocatalytic degradation pathway involved the hydrolysis reaction of the aliphatic chain and hydroxylation of the aromatic ring, obtaining products with lower toxicity than the initial molecules.
- Salazar-Beltrán, Daniel,Hinojosa-Reyes, Laura,Maya-Alejandro, Fernando,Turnes-Palomino, Gemma,Palomino-Cabello, Carlos,Hernández-Ramírez, Aracely,Guzmán-Mar, Jorge Luis
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p. 863 - 870
(2019/04/17)
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- Product-oriented chemical surface modification of a levansucrase (SacB): Via an ene-type reaction
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Carbohydrate processing enzymes are sophisticated tools of living systems that have evolved to execute specific reactions on sugars. Here we present for the first time the site-selective chemical modification of exposed tyrosine residues in SacB, a levansucrase from Bacillus megaterium (Bm-LS) for enzyme engineering purposes via an ene-type reaction. Bm-LS is unable to sustain the synthesis of high molecular weight (HMW) levan (a fructose polymer) due to protein-oligosaccharide dissociation events occurring at an early stage during polymer elongation. We switched the catalyst from levan-like oligosaccharide synthesis to the efficient production of a HMW fructan polymer through the covalent addition of a flexible chemical side-chain that fluctuates over the central binding cavity of the enzyme preventing premature oligosaccharide disengagement.
- Ortiz-Soto, Maria Elena,Ertl, Julia,Mut, Jürgen,Adelmann, Juliane,Le, Thien Anh,Shan, Junwen,Te?mar, J?rg,Schlosser, Andreas,Engels, Bernd,Seibel, Jürgen
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p. 5312 - 5321
(2018/06/27)
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- A hydroxy benzoic anhydride preparation method
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The invention discloses a preparation method of hydroxy benzene anhydride. The preparation method comprises the following steps: mixing nitrophthalonitrile and an organic solvent, adding alkali and nitrite, performing heating and a reflux reaction, and performing aftertreatment so as to obtain hydroxyl phthalonitrile; mixing the hydroxyl phthalonitrile and a KOH aqueous solution, performing heating, reflux and filtration, collecting filtrate, after the filtrate is cooled, regulating the pH to be 1, performing multiple extraction, taking an extraction liquid, and performing aftertreatment so as to obtain hydroxyl phthalic acid; and finally performing vacuum sublimation on the hydroxyl phthalic acid so as to obtain the hydroxy benzene anhydride. The simple preparation method of the hydroxy benzene anhydride, provided by the invention, is mild in reaction conditions, simple and convenient to operate, easy to control, low in equipment requirements and very high in yield.
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- Dental materials with improved hydrolysis stability based on phthalic acid monomers
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Dental material which contains a polymerizable phthalic acid derivative of the general Formula I: with R1=H, methyl or a C1-C5 alkyl residue; R2=H, a phenyl, benzyl or C1-C8 alkyl residue; Q1=is absent or is a C1-C15 alkylene residue, wherein the carbon chain can be interrupted by O or S; Q2=is absent or a (n+1)-valent aliphatic C1-C20 residue, wherein the carbon chain can be interrupted by O or S and wherein Q1 and Q2 cannot be absent simultaneously; X=is absent, is O, S or (—CO—NR4—)—, wherein R4 is H, CH3 or C2H5; Y=is absent, is O, S or (—CO—NR5—)—, wherein R5 is H, CH3 or C2H5; n, m=independently of one another in each case mean 1, 2 or 3; R3=H, CH3, C2H5, Cl, Br or OCH3, and wherein the two carboxyl groups of the benzene ring can together form an anhydride group.
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Page/Page column 8-9
(2016/08/17)
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- Synthesis and characterization of transparent polyimides derived from ester-containing dianhydrides with different electron affinities
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Two series of poly(ester imide)s derived from bis(trimellitic acid anhydride) phenyl ester (TAHQ) and bis[(3,4-dicarboxylic anhydride) phenyl] terephthalate (PAHP), as well as poly(ether imide)s based on hydroquinone diphthalic anhydride (HQDPA), were synthesized with aromatic diamines via solution polycondensation. These polyimide films were transparent with an ultraviolet-visible absorption cut-off wavelength below 375 nm, and with tensile strengths of 42.0-83.8 MPa, tensile moduli of 2.5-4.7 GPa and elongations at break of 2.1-5.4%. Compared with the poly(ether imide)s, the poly(ester imide)s showed higher glass transition temperatures (Tg), lower water absorption (WA) and lower temperature of 5% weight loss (Td5%). Moreover, the poly(ester imide)s derived from PAHP with a low electron affinity of 2.04 eV by theoretical calculation achieved better transparency, lower WA and slightly lower Tg than the corresponding TAHQ-based poly(ester imide)s.
- Zhou, Yu,Chen, Guofei,Wang, Wei,Wei, Lihong,Zhang, Qiuju,Song, Liping,Fang, Xingzhong
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p. 79207 - 79215
(2015/10/05)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- Dental materials with improved hydrolysis stability based on phthalic acid monomers
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Dental material which contains a polymerizable phthalic acid derivative of the general Formula I: with R1═H, methyl or a C1-C5 alkyl residue; R2═H, a phenyl, benzyl or C1-C8 alkyl residue; Q1=is absent or is a C1-C15 alkylene residue, wherein the carbon chain can be interrupted by O or S; Q2=is absent or a (n+1)-valent aliphatic C1-C20 residue, wherein the carbon chain can be interrupted by O or S and wherein Q1 and Q2 cannot be absent simultaneously; X=is absent, is O, S or (—CO—NR4—)—, wherein R4 is H, CH3 or C2H5; Y=is absent, is O, S or (—CO—NR5—)—, wherein R5 is H, CH3 or C2H5; n, m=independently of one another in each case mean 1, 2 or 3; R3═H, CH3, C2H5, Cl, Br or OCH3, and wherein the two carboxyl groups of the benzene ring can together form an anhydride group.
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Paragraph 0071; 0072; 0073; 0074
(2013/04/13)
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- Acid groups containing hydrolytically stable monomers
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Monomer compound (I) is new. Monomer compound (I) of formula (R 1>-O-CO-C(=CHR)-Y 1>-O-Q(AH) n) is new. Either A : -CO 2->or SO 3->; or A+H +>AH; Q : 1-12C alkylene, 4-12C alkylene (interrupted by -O-,=N- or -S) or 6-15C arylene (optionally substituted by 1-4C alkyl, 1-4C alkoxy or halo), where arylene and aryl groups further carries acid groups A; Y 1>1-12C alkylene or 4-12C alkylene (interrupted by -O-, =N- or -S); R : CH 3or H; R 1>1-6C alkylene; and n : 1-3. Independent claims are also included for: (1) preparation of (I); (2) a composition comprising (I), a polymerizable monomer, optionally one/more initiator, and a filler, pigment and/or stabilizer; and (3) a dental material (II) comprising (I).
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Page/Page column 4
(2008/06/13)
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- Vitamin D analogues
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The invention concerns novel bi-aromatic compounds having the formula: which are analogs of vitamin D, the process of preparing them, as well as their use in pharmaceutical compositions in human or veterinary medicine, particularly in dermatology, cancer treatment, treatment of auto-immune diseases, and in organ or tissue transplants. Cosmetic compositions and methods of use are also included.
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Page column 20
(2010/02/05)
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- Vitamin D analogues
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The invention relates to novel bicyclic compounds having the general formula (I): as well as to a method for preparing them and to their use in pharmaceutical compositions intended for use in human or veterinary medicine (in dermatology, in carcinology and in the field of autoimmune diseases and that of organ or tissue transplants in particular), or alternatively in cosmetic compositions.
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Page column 11
(2010/02/05)
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- Studies on the Chemistry of Isoindoles and Isoindolenines, XXVIII. - 3-Alkoxy-1H-isoindoles, Syntheses and Properties
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3-Alkoxy-1H-isoindoles 1 bearing substituents at the carboxylic moiety have been synthesized from substituted 2,3-dihydro-1H-isoindol-1-ones 4 by regiospecific O-alkylation to 5 with trialkyloxonium tetrafluoroborates or methyl trifluoroborates or methyl trifluoromethanesulfonate and subsequent NH deprotonation.According to the spectroscopic properties the semicyclic alkyl imidates 1 exist exclusively in the benzoid 1H structure; the tautomeric o-quinonoid 2H structure 2 cannot be detected by spectroscopic means.
- Hennige, Hans,Kreher, Richard P.,Konrad, Michael,Jelitto, Frank
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p. 243 - 252
(2007/10/02)
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