89-91-8Relevant academic research and scientific papers
DEUTERATED COMPOUNDS AS ROCK INHIBITORS
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Paragraph 105; 117, (2019/10/15)
Provided are compounds of Formular (I), or pharmaceutically acceptable salts thereof, pharmaceutical compositions comprising these compounds thereof, and use of these compounds in preparing drugs for inhibiting ROCK.
Direct conversion of cellulose to high-yield methyl lactate over Ga-doped Zn/H-nanozeolite Y catalysts in supercritical methanol
Verma, Deepak,Insyani, Rizki,Suh, Young-Woong,Kim, Seung Min,Kim, Seok Ki,Kim, Jaehoon
supporting information, p. 1969 - 1982 (2017/06/09)
For realizing sustainable bio-based refineries, it is crucial to obtain high yields of value-added chemicals via the direct conversion of cellulose and lignocellulosic biomass. Although the conversion of cellulose using homogeneous catalysts has been demonstrated to be quite successful, low cellulose conversion and poor product selectivity have been observed using heterogeneous catalysts. In this study, for the first time, the efficient conversion of cellulose to lactic acid derivatives, which can be used as a green solvent and a potential precursor for fine chemicals and biodegradable polymers, over a Ga-doped Zn/H-nanozeolite Y (Ga-doped Zn/HNZY) catalyst is described. Under optimized conditions at 280°C in supercritical methanol, methyl lactate (ML) and methyl 2-methoxypropionate (MMP) are obtained in yields of 57.8% and 12.8%, respectively, from cellulose; these values are greater than those reported in previous studies conducted using heterogeneous catalysts. Using oakwood, ML and MMP are obtained in yields of 12.3% and 18.6%, respectively. A large external surface area of the HNZY support and the synergistic effect of Ga doping on ZnO enhance Lewis acid sites with the simultaneous decrease of the Br?nsted acid sites. This unique catalyst (Ga-doped Zn/HNZY) is beneficial for controlling the consecutive reaction pathways of the decomposition of cellulose to glucose, retro-aldol condensation to trioses, and intramolecular Cannizzaro reaction to ML.
A double-nitroxide free radical preparation method and structural characterization
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Paragraph 0031-0036, (2017/01/19)
The invention discloses a preparation method of a novel triazoldinitrooxy radical, and structure characterization of the novel triazoldinitrooxy radical. The structure of the triazoldinitrooxy radical [3,5-di-(4,4,5,5-tetramethylimidazoline-3-oxide-1-oxy radical)-1H-1,2,4-triazole] is shown in the specification. The above synthesis route of the dinitrooxy radical disclosed in the invention has the characteristics of simple synthesis step, easy operation, high yield and the like. The above compound is a dinitrooxy radical having potential application values, has strong ferromagnetic interaction at a low temperature, and possibly becomes a new magnetic material used in the memory equipment for making computers.
Dissolution of wood in α-keto acid and aldehydic carboxylic acids and fractionation at room temperature
Nishiwaki-Akine, Yuri,Watanabe, Takashi
, p. 3569 - 3579 (2014/07/08)
Wood pulverised using a ball mill was dissolved in an α-keto acid, pyruvic acid, and two aldehydic carboxylic acids, namely glyoxylic acid and formic acid, at room temperature. Viscosity and optical transmittance analyses revealed that the wood particles dissolved in glyoxylic acid and formic acid in several hours, while they dissolved in pyruvic acid in several days. Size exclusion chromatography demonstrated that substances with number average molecular mass exceeding 105 were present in every solution. Incubation of these carboxylic acids with methanol produced the corresponding ester and/or (hemi)acetal derivatives, suggesting that the dissolution mechanism involves the substitution of hydroxyl groups in biomass. After dissolution, all solutions demonstrated non-Newtonian fluid behaviour with a non-Newtonian index n ranging from 0.41 to 0.72. When the dissolution time increased, the non-Newtonian index of the formic acid solution increased towards the value for a Newtonian fluid (n = 1). This rise was accompanied by partial depolymerisation. Evaporation of the wood solution gave a smooth transparent film. Using the water-immiscible solvent 2-methyltetrahydrofuran (2-MeTHF), the formic acid solution was separated into cellulosic porous solids, lignin-rich 2-MeTHF-soluble fraction and other components at room temperature. The dissolution of woody biomass at room temperature creates a new biorefinery process for the conversion of wood components in various solution reactions. In particular, in this study, pyruvic acid, which plays a central role in the metabolism of living organisms, is used as a new solvent for wood, thus bridging biochemistry and wood biorefinery. This journal is the Partner Organisations 2014.
Syntheses of 3,4-benzotropolones by ring-closing metatheses
Arican, Deniz,Brückner, Reinhard
supporting information, p. 2582 - 2585 (2013/07/19)
Ortho-lithiated styrenes or ortho-lithiated benzaldehyde dimethyl acetals were added to 2,2-dimethoxypent-4-enals 7. The resulting alcohols were carried on to the aromatic dienones 10. These were ring-closed by olefin metathesis. Hydrolysis of the dimethyl ketal moiety and enolization provided the 3,4-benzotropolones 5. Overall, this access comprises 4-6 steps and totaled a 22-81% yield.
Conversion of levulinate into succinate through catalytic oxidative carbon-carbon bond cleavage with dioxygen
Liu, Junxia,Du, Zhongtian,Lu, Tianliang,Xu, Jie
, p. 2255 - 2258 (2014/01/06)
Grand Cleft Oxo: Levulinate, available from biomass, is oxidized into succinate through manganese(III)-catalyzed selective cleavage of C-C bonds with molecular oxygen. In addition to levulinate, a wide range of aliphatic methyl ketones also undergo oxidative C-C bond cleavage at the carbonyl group. This procedure offers a route to valuable dicarboxylic acids from biomass resources by nonfermentive approaches. Copyright
Vinylic Substitution of 1,2-Dibromo-1,2-difluoroethylene and Tribromofluoroethylene. An Intramolecular kBr/kF Element Effect and Apparent Inversion of Configuration in SNV Reactions
Shainyan, Bagrat A.,Rappoport, Zvi
, p. 3421 - 3428 (2007/10/02)
The reactions of (E/Z)-1,2-dibromo-1,2-difluoroethylene(1) and of tribromofluoroethylene (2) with alkoxide ions and of 1 with p-toluenethiolate ion give multiplicity of products.The reaction of 1 with 1 equiv of NaOMe gives mainly a 2:1 mixture of the product of one bromine displacement, together with methyl dimethoxyacetate (3), methyl bromofluoroacetate (4), 1,1,2-trifluoro-2-bromoethyl ether (7), and 1,1-difluoro-1,2,2-trimethoxyethane (8).With 2 equiv of MeO(1-) 3 and 4 are the main products, and at 130 deg C, dimethyl ether 5 is also formed.With EtOCH2CH2O(1-) 1 gave 2-ethoxyethyl bromofluoroacetate (9), bis(2-ethoxyethyl) ether (10), and E/Z mixtures of the substitution products EtOCH2CH2OC(F)=C(F)Br (12) and EtOCH2CH2OC(Br)=C(F)Br (13).Reaction of 2 with excess RO(1-) (R = Me, Et) gives alkyl dibromoacetates, while with 1 equiv of RO(1-) only a bromine from the =C(F)Br carbon is displaced.Reaction of 1 with p-TolSNa in MeOH gives the reduction-substitution product p-TolSC(F)=CHF (18), together with (P-TolS)2 (16) and p-TolSMe (17).The same reaction in DMSO gives E/Z mixtures of the product of displacement of one bromine (19) or two bromines (20).Formation of the products is rationalized by an initial nucleophilic attack on the vinylic carbon followed by leaving group expulsion, giving, e.g., 12, 13, 19, or 20.Hydrolysis of the intermediate or addition of HF to the initial substition product gives saturated products, e.g., 3, 4, 7, or 8, while SN2 reactions on the ether oxygen give ethers 5 and 10.A bromophilic reaction gives the reduction-substitution product 18, while hydrolysis-decarboxylation leads to 17.The regiospecificity of the nucleophilic addition is due to polar and hyperconjugative effects.An intramolecular element effect kBr/kF of > 10 is reported for the first time in the reaction of 1 with EtOCH2CH2O(1-).This value and the absence of such effects in other reactions are consistent with a much higher nucleofugality from a (1-)CC(F)Br system of Br(1-) compared with F(1-).The E/Z compositions of 18-20 indicates an apparent inversion in their formation, but it is not known whether these compositions are thermodynamically or kinetically controlled.
Bis-trimethylsilylacetamide: A reagent for the control of Friedel-Crafts alkylation reactions using methyl chloromethoxyacetate
Earle, Martyn J.,Fairhurst, Robin A.,Heaney, Harry
, p. 6171 - 6174 (2007/10/02)
The Friedel-Crafts alkylation reactions of electron rich aromatic compounds using methyl α-chloro-α-methoxyacetate and Lewis acids leads predominantly to the formation of diarylacetic acid derivatives in which the second stage of the sequence is favoured by the presence of hydrogen chloride generated in the first step; effective control can be achieved in a number of cases by the addition of bis-trimethylsilylacetamide.
3-(2-Pyrrolidinyl)-2,4-furandione Analogs
Coppola, Gary M.,Damon, Robert E.
, p. 815 - 817 (2007/10/02)
The reaction of 4,4-dimethyl-3-oxobutanoic (or pentanoic) acid esters with the lactim ether of 2-pyrrolidone in the presence of 2-hydroxypyridine produces condensation products 4 in 57-72percent yield.Acidic hydrolysis of 4 affords the furandione system 5 in 75-81percent yield.
Acid-catalyzed hydrolysis of tetramethoxyethene in aqueous solution. Initial state stabilization by the methoxy groups
Kresge, A. J.,Leibovitch, M.,Kopecky, K. R.
, p. 1786 - 1790 (2007/10/02)
The acid-catalyzed hydrolysis of tetramethoxyethene to methyl dimethoxyacetate in aqueous solution at 25 deg C was found to occur with the hydronium-ion coefficient kH+ = 0.454 M-1s-1, to give the solvent isotope effect kH+/kD+ = 3.15, and to provide a Bronsted relation based upon six carboxylic acids with the exponent α = 0.42.These data indicate that the reaction proceeds via rate-determining proton transfer from the catalyzing acid to an olefinic carbon atom of the substrate.They also show tetramethoxyethene to be 1.0 * 1E6 times less reactive than 1,1-dimethoxyethene (ketene dimethyl acetal), a rate retardation 600 times greater than that expected from initial state stabilization by the two additional methoxy groups in tetramethoxyethene; possible causes of this disparity are discussed.
