- Synthesis of racemic mandelic acids with the composite phase transfer catalyst β-cyclodextrin-[bmim]PF6
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Ionic liquids were employed as a part of composite phase transfer catalyst to synthesise mandelic acid, and it is found that [bmim]PF6 coupled with β-cyclodextrin is the most effective catalyst, which was also applicable to other reactions used to synthesise mandelic acid derivatives. Reaction conditions were optimized and the products were characterised by 1H NMR and IR.
- Yang, Ben-Yong,Yang, De-Hong
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- Metal ion catalysis in the hydroxyalkylation of phenol with glyoxylic acid
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The hydroxyalkylation reaction of phenol with glyoxylic acid in aqueous medium is found to be homogeneously catalyzed by various metal ions.Catalysis with MII ions results in a reaction product with an ortho/para ratio of 0.2 to 1.1, whereas catalysis using higher valent cations, because of their ability to form mixed complexes with phenol and glyoxylic acid, affords a reaction product with an ortho/para ratio 1.3 to 28.The catalyzed Cannizzaro reaction of glyoxylic acid was observed as a side-reaction.Addition of a suitable inert ligand, e. g. oxalic acid or NTA, is shown to decrease the ortho/para ratio and suppress the Cannizzaro reaction.The coordination of glyoxylic acid and its hydrate with several cations has been studied by NMR techniques and a mechanism of the catalyzed hydroxyalkylation and Cannizzaro reaction is proposed.
- Hoefnagel, A. J.,Peters, J. A.,Bekkum, H. van
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- Preparation method of P-hydroxybenzaldehyde
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The invention relates to a preparation method of p-hydroxybenzaldehyde, which comprises the steps of (1) by taking aluminum salt and/or zinc salt as a catalyst, carrying out condensation reaction on phenol and glyoxylic acid under an alkaline condition to obtain 4-hydroxymandelic acid; and (2) oxidizing 4-hydroxymandelic acid serving as a raw material with copper ferrite serving as a catalyst to obtain p-hydroxybenzaldehyde. Compared with the prior art, the method has the advantages of easily available raw materials, mild reaction conditions, high yield and the like.
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Paragraph 0051-0065; 0068-0070; 0072-0074; 0076-0077; ...
(2021/07/17)
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- Butenolide derivative as well as preparation method and application thereof
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The invention discloses a butenolide compound as well as a preparation method and an application thereof. The butenolide derivative has the inhibitory activity of protein tyrosine phosphatase 1B (PTP1B), improves insulin resistance of HepG2 cells, generates a remarkable hypoglycemic effect and can be used for preparing a medicine for treating diabetes mellitus.
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Paragraph 0045-0048
(2020/07/21)
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- Synthesis of mandelic acid derived phthalimides as a new class of antiinflammatory and antimicrobial agents
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In the present study, a new series of 2-(1,3-dioxo-2,3-dihydro-1H-2- isoindolyl) ethyl 2-hydroxy-2-(substituted phenyl) acetates 6a-e have been synthesized from the combination of N-(2-hydroxy ethyl) phthalimide 5 and substituted mandelic acids 2a-e which resulted in both anti-inflammatory and antimicrobial activity. These compounds have been characterized by IR, 1H NMR, mass spectral and elemental analysis. Among the compounds tested for anti-inflammatory activity, compound 6b and 6c showed significant activity and compound 6d showed potent antibacterial and antifungal activity. The anti-inflammatory activity has been determined by carrageenan induced acute paw oedema in rats. The results are discussed in the text. The in vitro antibacterial and antifungal activity of the compounds have been evaluated by paper disc diffusion method. The minimum inhibitory concentrations (MIC) of the compounds have also been determined by agar streak dilution method.
- Varala, Ravi,Kotra, Vijay,Alam, M. Mujahid,Kumar, N. Ramesh,Ganapaty,Adapa, Srinivas R.
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p. 1243 - 1248
(2008/12/23)
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- Method for producing optionally substituted aliphatic, aromatic or heteroaromatic aldehydes
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The invention relates to a method for producing optionally substituted aliphatic, aromatic or heteraromatic aldehydes of formula (I), whereby the R represents a C1-C20 Alkyl radical, an aromatic or heteraromatic radical Ar which can optionally be substituted once or on a number of occasions by OH, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 carboxylic acids or ester containing 1-6 C atoms in the ester part, phenyl, halogen, SO3H, NO2, NR1R2 or SR1 whereby R1 and R2 can be independently H, phenyl or C1-C6 alkyl. The invention is characterised by a compound of formula (II) wherein R has the above meaning, a) is diazotized in an acidic medium, at a temperature of between ?10 ?+100 ° C. by a diazoation reagent and is transformed into the corresponding hydroxy carboxy acid whereby b) is transformed, by means of oxygen, into the appropriate aldehyde of formula (I) in the presence of a metal, the salt thereof, oxide or hydroxide as a catalyst.
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- Activity-based fluorescent probes that target phosphatases
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We have successfully designed and synthesized two fluorescently-labeled, activity-based probes, Probe 1 and Probe 2, which were shown to label protein tyrosine phosphatases specifically, as well as other types of phosphatases. The probes were not reactive towards the other non-phosphatase enzymes tested. These probes may find potential applications in large-scale proteomic experiments whereby subclasses of proteins may be selectively identified.
- Zhu, Qing,Huang, Xuan,Chen, Grace Y. J.,Yao, Shao Q.
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p. 2669 - 2672
(2007/10/03)
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- Method of preparing 2- and 4-hydroxymandelic acid
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The invention relates to a method of preparing 2- and 4-hydroxymandelic acid by condensing glyoxylic acid with phenol. The glyoxylic acid is reacted with phenol, after which the formed reaction mixture or the phenol, the 2- and 4-hydroxymandelic acid respectively are elution-separated in a column comprising an anion exchange resin, wherein first the excess phenol is separated, followed by the separation of the 4-hydroxymandelic acid and finally the 2-hydroxymandelic acid, both in the form of acid and salt, depending on the eluent used.
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Page column 6
(2008/06/13)
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- Separation of 2- and 4-hydroxymandelic acid
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Hydroxyalkylation of phenol with glyoxylic acid, catalyzed by AlIII, results, under neutral aqueous conditions, in ortho-rich mixtures of hydroxymandelic acids. Para-rich mixtures of hydroxymandelic acids are obtained by ZnII catalysis under slightly alkaline conditions. A new separation method of these mixtures into the pure alkali salts of 2- and 4-hydroxymandelic acid is presented. Formation of a complex between the alkali ion and three co-operating oxygen atoms of 2-hydroxymandelate explains the excellent solubility of the ortho isomer in acetone, enabling extraction of this isomer selectively from mixtures of alkali salts of 2- and 4-hydroxymandelic acid.
- Hoefnagel,Peters,Van Bekkum
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p. 353 - 356
(2007/10/03)
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- Biofungicidal composition
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The invention relates to a biofungicidal composition characterized by its capacity to arrest the growth and/or destroy the cell wall of pathogenic fungi, comprises a composition of a compound of the formula I STR1 wherein R1 is selected from the group consisting of STR2 and R2 is --H or --OH and mixtures thereof in association with an inert carrier, and to a method for arresting the growth and/or destroying the cell wall of pathogenic fungi by applying thereto a biofungicidal amount of the composition of a compound of formula I in association with an inert carrier.
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- Oxidation of Mandelic Acid by Fenton's Reagent
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Mandelic acid forms a stable 1:1 complex with Fe2+ at pH 1-3.Its oxidation by H2O2 and S2O82- has been investigated in the hope of detecting intramolecular oxidation-reduction of any intermediate FeIV species, rather than the usual hydroxyl radical process.Products are benzaldehyde and hydroxymandelic acids, consistent with either, but added hydroxyl radical traps - acetone or crotonic acid - are able to intercept only about half of the reaction.However, they reduce yields of benzaldehyde but not hydroxymandelic acids, and it is concluded that the balance of the reaction involves cage reactions of newly formed hydroxyl radicals rather than a high-valence iron species.
- Walling, Cheves,Amarnath, Kalyani
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p. 1185 - 1189
(2007/10/02)
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- Process for the manufacture of phenylacetic acid and simple derivatives thereof
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Phenylacetic acid and the simple derivatives thereof are prepared by catalytic hydrogenation of mandelic acid and its appropriate derivatives in the presence of a noble metal catalyst in aqueous solution which is free from mineral acid, especially free from hydrochloric acid.
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- HYPERVALENT IODINE IN ORGANIC SYNTHESIS. A NEW ROUTE TO α-FUNCTIONALIZED CARBOXYLATE ESTERS.
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Aryl and alkylcarboxylate esters are converted into the corresponding α-hydroxy acids or α-alkoxyesters upon treatment with C6H5I(OAc)2 and base in the appropriate solvent.
- Moriarty, Robert M.,Hu, Henry
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p. 2747 - 2750
(2007/10/02)
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- 7-α-Amino-substituted acylamino-3-(1-carboxymethyltetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids
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Certain 7-acylamido-3-(1-carboxy-loweralkyl-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids and their salts and easily hydrolyzed esters of the 4-carboxyl group were synthesized and found to be potent antibacterial agents which exhibited good aqueous solubility. In a preferred embodiment the 7-substituent was 2'-aminomethylphenylacetamido.
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- Process for preparing aromatic hydroxyaldehydes
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Aromatic hydroxy aldehydes are prepared by the simultaneous oxidation and decarboxylation of hydroxy aryl glycolic acids by reacting same with oxidizing agents in aqueous-acid medium.
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- 7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo-[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives
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7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives containing blocking groups on the α-hydroxy group and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and in animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria. A preferred compound is 7-(D-mandelamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acid.
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- 7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids
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7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria.
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