- A aldehyde or mellow directly converted into the carboxylic acid (by machine translation)
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The invention discloses a aldehyde or mellow oxidation can be directly transformed into carboxylic acid, is characterized in that the pure oxygen environment, in N - hydroxy imide compound under the catalysis of the imide compound or N - hydroxy and nitrous acid ester compound common under the catalysis, the CH2 OH and CHO oxidation directly converted into the carboxylic acid compounds. The invention using oxygen as the oxidizing agent, does not add any metal catalyst, environment-friendly, high catalytic efficiency, simple and convenient operation. With the previous metal catalytic system complex and different catalytic system, has some metal catalytic system in the process, the use of transition metal will cause the transition metal of the residual, the invention adopts the non-metallic catalytic system, environmental protection, preventing the metal residue problem, this to the solution of the drug in the synthesis of transition metal residue problem and provides a new method of thinking. (by machine translation)
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Paragraph 0068-0070
(2018/08/03)
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- METHOD OF MAKING ACRYLIC ACID FROM LACTIC ACID OR LACTIDE USING MOLTEN SALT CATALYSTS
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A method of making acrylic acid in liquid phase by contacting a feed stream containing lactic acid, lactide, or mixtures thereof with a molten salt catalyst comprising a protic ionic liquid (PIL), which contains a bromide anion (Br-), is provided.
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Page/Page column 42-54
(2018/09/28)
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- Catalytic Bromination of Alkyl sp3C-H Bonds with KBr/Air under Visible Light
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Alkyl sp3C-H bonds of cycloalkanes and functional branch/linear alkanes have been successfully brominated with KBr using air or O2 as an oxidant at room temperature to 40 °C. The reactions are carried out in the presence of catalytic NaNO2 in 37% HCl (aq)/solvent under visible light, combining aerobic oxidations and photochemical radical processes. For various alkane substrates, CF3CH2OH, CHCl3, or CH2Cl2 is employed as an organic solvent, respectively, to enhance the efficiency of bromination.
- Zhao, Mengdi,Lu, Wenjun
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supporting information
p. 5264 - 5267
(2018/09/12)
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- Preparation method of alkane brominated material
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The invention relates to a preparation method of an alkane brominated material. The preparation method comprises the following steps: adding alkane, a bromine-containing compound or elemental bromine,a catalyst and acid into a solvent; adding the solvent into a light-transmission reaction container under air or oxygen atmosphere; sealing; performing stirring reaction under constant pressure and light illumination conditions; then analyzing a nuclear magnetic yield, and performing extraction, drying, filtration, distillation under reduced pressure and column separation to obtain the alkane brominated material. Compared with the prior art, the preparation method disclosed by the invention has the advantages that by using low-cost and safe bromic salt as a bromine source, the air as an oxidizing agent and a nitrogen-containing reagent as the catalyst, reaction is carried out under the conditions of constant temperature and constant pressure, so that energy conservation and economy are realized, and the preparation method is convenient and safe to operate and is environmentally friendly.
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Paragraph 0067-0068
(2018/09/08)
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- METHODS OF MAKING ACRYLIC ACID FROM LACTIC ACID OR ITS DERIVATIVES IN LIQUID PHASE
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Methods for making acrylic acid, acrylic acid derivatives, or mixtures thereof by contacting a feed stream containing lactic acid, lactic acid derivatives, or mixtures thereof with a molten salt catalyst comprising an ionic liquid (IL) and an acid in liquid phase are provided.
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Page/Page column 67
(2018/02/28)
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- CATALYSTS FOR MAKING ACRYLIC ACID FROM LACTIC ACID OR ITS DERIVATIVES IN LIQUID PHASE
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Catalysts for the dehydration of lactic acid, lactic acid derivatives, or mixtures thereof to acrylic acid, acrylic acid derivatives, or mixtures thereof in liquid phase comprising an ionic liquid (IL) and an acid are provided.
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Page/Page column 67
(2018/02/28)
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- A versatile and stereocontrolled total synthesis of dihydroxylated docosatrienes containing a conjugated E,E,Z-triene
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A versatile strategy featuring a Colvin rearrangement, hydrozirconation, a Sonogashira cross-coupling reaction and a Z-selective Wittig olefination, was successfully developed for the construction of a conjugated E,E,Z-triene subunit, flanked on both sides by two Z-allylic hydroxyl groups. This chemical pattern is found in many endogenous lipid metabolites such as maresin1 (MaR1), neuroprotectinD1 (NPD1), and its aspirin triggered-isomer AT-NPD1, which not only counter-regulate inflammation but also actively orchestrate (at nanomolar doses) the resolution and termination program of acute inflammation while promoting wound healing, return to homeostasis and neuroprotection. Unlike previous approaches, the advantages of the present strategy are obvious, as it allows us to modify the nonpolar tail, the carboxylated head or both ends of the molecule without repeating the whole synthetic sequence (about 26-34steps according to the literature). Thus, the first total syntheses of NPD1 methyl ester epimer (which can also be considered as an enantiomer of AT-NPD1) and its n-3 docosapentaenoic acid derived analogue were achieved from a highly functionalized and late advanced pivotal intermediate. This innovative route may be easily adapted to gain access to other dihydroxylated metabolites and analogues of polyunsaturated fatty acids containing a conjugated E,E,Z-triene subunit. Different epimers/diastereoisomers may be obtained by purchasing the suitable optically pure (S)- and/or (R)-1,2,4-butanetriol(s) as a chiral pool for both stereogenic centers. Modification is key: Two total syntheses of dihydroxylated and noncyclic metabolites of polyunsaturated fatty acids, that is, NPD1 methyl ester epimer and its n-3 docosapentaenoic acid (DPA)-derived analogue, were achieved from a highly functionalized and late advanced pivotal intermediate (see scheme).
- Dayaker, Gandrath,Durand, Thierry,Balas, Laurence
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supporting information
p. 2879 - 2887
(2014/03/21)
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- Synthesis of [3-13C]-, [4-13C]- and [11- 13C]-porphobilinogen
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[4-13C]-porphobilinogen 1a, [3-13C]-porphobilinogen 1b and [11-13C]-porphobilinogen 1c are prepared from [1- 13C]-3-(tetrahydropyran-20-yloxy)-propionaldehyde 2a, methyl [4- 13C]-4-nitrobutyrate 3b and [1-13C]-isocyanoacetonitrile 5c, respectively. The building blocks 2, 3 and 5 can be prepared efficiently in any isotopomeric form. Via base-catalyzed condensation of these building blocks porphobilinogen can be enriched with 13C and 15N stable isotopes at any position and combination of positions. Copyright
- Dawadi, Prativa B. S.,Schulten, Els A. M.,Lugtenburg, Johan
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experimental part
p. 341 - 349
(2011/07/08)
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- An efficient method for the synthesis of aliphatic acids using microwaves
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Aliphatic acids are prepared by reaction of nitriles with phtalic acid by irradiation under microwaves in a domestic oven.
- Brǎtulescu, George
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p. 161 - 163
(2007/10/03)
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- Montmorillonite clay: A novel reagent for the chemoselective hydrolysis of t-butyl esters
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A mild and highly selective hydrolysis of t-butyl esters has been achieved in high yields using montmorillonite KSF in refluxing acetonitrile. The method is compatible with a variety of protecting and functional groups such as BOC, Cbz, propargyl, allyl, benzyl, t-butyl ethers, allyl, methyl and benzyl esters present in the molecule.
- Yadav,Reddy, B. V. Subba,Rao, K. Sanjeeva,Harikishan
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p. 826 - 828
(2007/10/03)
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- Acyl Substituent Effects on Rates of Acyl Transfer to Thiolate, Hydroxide, and Oxy Dianions
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The rates of transfer of a series of polar aliphatic acyl groups (-0.3 (*) (*) (*) 1.05) from p-nitrophenol to hydroxide, to the thiol anion of N-acetyl-L-cysteine, and to a series of phosphonate dianions have been determined in aqueous solution.The rate constants for the alkaline hydrolysis of ten p-nitrophenyl esters can be correlated reasonably well (r = 0.981) to the single-parameter Hammett-Taft equation based on the polar substituent constant.The reaction constant for the alkaline hydrolysis is (*) = 2.9 with an interval estimator (90percent confidence) of +/-0.3.The (*) value for the thiolysis reaction is only slightly larger (16 +/- 13percent) than the corresponding value for the alkaline hydrolysis reaction.These kinetic (*) values are essentially identical with the equlibrium (*) for hydroxide or thiolate addition to aldehydes (Kanchuger and Byers).To the extent that gem diolate and thiohemiacetalate formation are appropriate model reactions for the formation of the anionic tetrahedral intermediates in the corresponding acyl transfer reactions, the magnitude of the kinetic (*) values suggests that the transition states for the alkaline hydrolysis and for the thiolysis reactions are similar, in geometry and charge distribution, to the intermediates.Acyl transfer from p-nitrophenol to phosphonate dianions involves an uncatalyzed nucleophilic displacement by the oxy dianion.The (*) value for the reaction of (chloromethyl)phosphonate with the p-nitrophenyl esters is 2.4 (+/-0.3).The second-order rate constants for the reactions between the phosphonates and p-nitrophenyl acetate, p-nitrophenyl chloroacetate, and p-nitrothiophenyl acetate show a small sensitivity to the basicity (pKa2) of the nucleophile (βnuc ca. 0.3).An explanation of the magnitudes of the (*) and βnuc values, and of the anomalously low reaction rates (relative to oxy monoanions and amines of comparable basicities) for acyl transfer to the phosphonates, is that electrostatic interactions and desolvation of the oxy dianion make substantial contributions to the activation energy barrier for nucleophilic attack.
- Shames, Spencer L.,Byers, Larry D.
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p. 6170 - 6177
(2007/10/02)
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- Effect of Phosphono Substituents on Acyl Transfer Reactions
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The rate of release of p-nitrophenoxide from esters of phosphono-substituted carboxylic acids was examined as a function of pH(D), temperature, divalent metal ion (Mg2+ and Ca2+) concentration, and acyl acceptor (-OH and the thiolate of N-acetylcysteine).The hydrolysis of p-nitrophenyl 3-phosphonopropionate involves intramolecular nucleophilic catalysis by the dianionic phosphono substituent (pKa2(*) = 7.5) and is characterized by a first-order rate constant of 94 min-1 at 37 deg C.A comparison of the rate constant of the unimolecular reaction with that of the corresponding bimolecular reaction (corrected for the inductive effect of the acyl substituent and for the phosphonate basicity) yields a rate constant ratio of kuni/kbi = 7(+/-6)*103 M.The magnitude of this rate enhancement is similar to those of analogous intramolecular reactions (e.g., hydrolysis of mono-p-nitrophenyl succinate or of p-nitrophenyl 4-(N,N-dimethylamino)butyrate but, unlike these reactions, the rate acceleration resulting from intramolecular nucleophilic catalysis by the dianionic phosphono group is enthalpic in origin (Δ(*) ca. 8 kcal/mol).The entropy of activation for the intramolecular reaction is less favorable than that for the bimolecular reaction (Δ(*) ca. 9 eu).The alkaline hydrolysis and the thiolysis rates of p-nitrophenyl phosphonoacetate are accelerated over 100-fold by the association of Mg2+ or Ca2+ with the ester.This rate acceleration is attributed to the formation of a six-membered bidentate coordination complex between the divalent cation and the incipient tetrahedral intermediate.The metal-promoted acyl transfer reactions of p-nitrophenyl phosphonoacetate provide a convenient system for the quantitative assessment of the role of metal ions in the catalysis of aqueous reactions.
- Shames, Spencer L.,Byers, Larry D.
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p. 6177 - 6184
(2007/10/02)
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- Action d'organolithiens et organomagnesiens sur la propiolactone en presence de sel cuivreux Synthese d'acides carboxyliques
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Organocuprate reagents, as well as Grignard reagents under the catalytic action of copper bromide, react with propiolactone to give the corresponding homologous acid with three more carbon atoms in good yields.
- Normant, J. F.,Alexakis, A.,Cahiez, G.
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p. 935 - 938
(2007/10/02)
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- α-AMINOACYL CONTAINING NEW PEPTIDES WITH GASTRIN EFFECTS AND A PROCESS FOR THE PREPARATION THEREOF
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Peptides of the formula: wherein A is tert.-butoxycarbonyl-aminooxy-acyl, benzyloxycarbonyl-aminooxy-acyl, (aminooxy)-acyl, or E-aminooxy-acyl, wherein E is benzoyl or straight-chain or branched C1-5 aliphatic acyl, B is methionyl, leucyl, norleucyl, norvalyl or 2-amino-decanoyl, and Y is hydrogen or carboxymethoxy, and pharmaceutically acceptable acid-addition salts or complexes thereof have gastric-acid secretion increasing effects.
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- Cephalosporin derivatives
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New cephalosporin derivatives containing a formyl substituted pyrrole group and the processes for preparing same are described.
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