90-64-2Relevant articles and documents
High-yield DL-mandelic acid synthesis process
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Paragraph 0021-0026, (2021/09/04)
The invention provides a high-yield DL-mandelic acid synthesis process. The synthesis process specifically comprises the following steps: 1, treating benzaldehyde by using sodium hydrogen sulfite to obtain benzaldehyde sodium hydrogen sulfite; 2, extracting the benzaldehyde sodium hydrogen sulfite by using an organic solvent, recovering unreacted benzaldehyde in the benzaldehyde sodium hydrogen sulfite, and adding sodium cyanide after the extraction is completed to prepare mandelonitrile; 3, adding an inorganic acid, and then carrying out heating and pressure maintaining treatment to hydrolyze the mandelonitrile so as to obtain mandelic acid; and 4, purifying the mandelic acid. According to the method, the step of extracting the p-benzaldehyde sodium hydrogen sulfite salt is added, so that the probability that the product purity is reduced due to benzoin condensation is reduced, the recycled benzaldehyde can be returned to the raw material for use, and the yield can be increased in multiple rounds of reactions; and the hydrolysis process of the mandelonitrile adopts heating and pressure maintaining treatment, so that consumption of inorganic acid can be reduced, and the hydrolysis efficiency is improved.
Designing of amino functionalized imprinted polymeric resin for enantio-separation of (±)-mandelic acid racemate
Alhawiti, Aliyah S.,Monier,Elsayed, Nadia H.
, (2021/02/12)
S-Mandelic acid (MA) enantio-selective resinous material functionalized with –NH2 groups has been developed and effectively utilized in chiral separation of (±)-MA racemate solution. S-MA has first combined with the polymerizable p-aminophenol and form the corresponding amide derivative, which was then polymerized with phenol/formalin using HCl as a catalyst. The stereo-selective –NH2 functionalized binding sites were then generated within the resin upon the alkaline degradation of the amide linkages followed by acidic treatments that will expel the resin incorporated S-MA out of the polymeric material to get the S-MA imprinted polymer (S-MAPR). The synthesized S-MA chiral amide derivative along with the developed polymeric resin was investigated by various techniques including FTIR and NMR spectra that confirmed the executed chemical modifications. In addition, the morphological appearance of the obtained resins were observed using SEM images. Moreover, the S-MAPR resin was examined to optimize the enantio-selective separation conditions and the studies indicated that the adsorption reached the highest value at pH 7 and the maximum capacity was 243 ± 1 mg/g. In addition, the chiral separation of (±)-MA racemic solution was successfully executed by the S-MAPR separation column with 55% and 82% enantiomeric excess of R- and S-MA within both the initial loading and recovery eluant solutions, respectively.
Synthesis of α-hydroxycarboxylic acids from various aldehydes and ketones by direct electrocarboxylation: A facile, efficient and atom economy protocol
Singh, Kishanpal,Sohal, Harvinder Singh,Singh, Baljit
, p. 839 - 845 (2021/04/09)
In present work, the formation of α-hydroxycarboxylic acids have been described from various aromatic aldehydes and ketones via direct electrocarboxylation method with 80-92% of yield without any side product and can be purified by simple recrystallization using sacrificial Mg anode and Pt cathode in an undivided cell, CO2at (1 atm) was continuously bubbled in the cell throughout the reaction using tetrapropylammonium chloride as a supporting electrolyte in acetonitrile. The synthesized compounds obtained in fair to excellent yield with a high level of purity. The characterization of electrocarboxylated compounds was done with spectroscopic techniques like IR, NMR (1H & 13C), mass and elemental analysis.
Method for synthesizing mandelic acid
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Paragraph 0032; 0034-0035; 0037-0038; 0040-0041; 0043, (2021/02/06)
The invention relates to the technical field of compound preparation, and provides a method for synthesizing mandelic acid, which comprises the following steps: by using styrene as a basic raw material, trichloroisocyanuric acid as a chlorinating agent an
Expanding the repertoire of nitrilases with broad substrate specificity and high substrate tolerance for biocatalytic applications
Rayavarapu, Pratima,Shah, Shikha,Sunder, Avinash Vellore,Wangikar, Pramod P.
, p. 289 - 296 (2020/05/18)
Enzymatic conversion of nitriles to carboxylic acids by nitrilases has gained significance in the green synthesis of several pharmaceutical precursors and fine chemicals. Although nitrilases from several sources have been characterized, there exists a scope for identifying broad spectrum nitrilases exhibiting higher substrate tolerance and better thermostability to develop industrially relevant biocatalytic processes. Through genome mining, we have identified nine novel nitrilase sequences from bacteria and evaluated their activity on a broad spectrum of 23 industrially relevant nitrile substrates. Nitrilases from Zobellia galactanivorans, Achromobacter insolitus and Cupriavidus necator were highly active on varying classes of nitriles and applied as whole cell biocatalysts in lab scale processes. Z. galactanivorans nitrilase could convert 4-cyanopyridine to achieve yields of 1.79 M isonicotinic acid within 3 h via fed-batch substrate addition. The nitrilase from A. insolitus could hydrolyze 630 mM iminodiacetonitrile at a fast rate, effecting 86 % conversion to iminodiacetic acid within 1 h. The arylaliphatic nitrilase from C. necator catalysed enantioselective hydrolysis of 740 mM mandelonitrile to (R)-mandelic acid in 4 h. Significantly high product yields suggest that these enzymes would be promising additions to the suite of nitrilases for upscale biocatalytic application.
Preparation of α-hydroxyphenylacetic acid with cyclodextrins as an effective phase-transfer catalyst and its reaction mechanism
Tian, Bing Ren,Zhang, Rui Xia,Chu, Hui Min,Huang, Qing,Wang, Zhi Zhong
, p. 359 - 368 (2019/05/16)
An effective procedure for the synthesis of α-hydroxyphenylacetic acid with cyclodextrin (CD) catalysts was developed. The phase-transfer catalyst types, catalyst loadings, reaction times, reaction temperatures, and substrate molar ratios were investigated to optimize the reaction conditions. In addition, the factors that affect the reaction were studied, and the relationship between benzaldehyde and β-cyclodextrin (β-CD) was analyzed through 2D-ROESY. The equilibrium constant when β-CD was used as the catalyst was calculated. The results indicated that β-CD is the optimal catalyst for the reported reaction (yield: 69.08%). Furthermore, the mechanism underlying the reported reaction was proposed.
Three-Component Synthesis of Isoquinoline Derivatives by a Relay Catalysis with a Single Rhodium(III) Catalyst
Zhou, Chao,Jiang, Jijun,Wang, Jun
supporting information, p. 4971 - 4975 (2019/09/03)
A rhodium(III)-catalyzed one-pot three-component reaction of N-methoxybenzamide, α-diazoester, and alkyne was developed, providing an alternative way to synthesize isoquinoline derivatives. Mechanistically, it is a relay catalysis, and the reaction occurred via successive O-alkylation and C-H activation processes, both of which were promoted by the same catalyst.
Thiamine Diphosphate Dependent KdcA-Catalysed Formyl Elongation of Aldehydes
Germer, Philipp,Gauchenova, Ekaterina,Walter, Lydia,Müller, Michael
, p. 4276 - 4280 (2019/08/02)
The formose reaction, one of the oldest name reactions in organic chemistry, uses formaldehyde as a C1 unit resulting in different monosaccharides and sugar-like compounds. Nucleophilic formyl elongation is an attractive option to obtain 1,2-fu
Characterization of a new nitrilase from Hoeflea phototrophica DFL-43 for a two-step one-pot synthesis of (S)-β-amino acids
Zhang, Zhi-Jun,Cai, Rui-Feng,Xu, Jian-He
, p. 6047 - 6056 (2018/05/15)
A nitrilase from Hoeflea phototrophica DFL-43 (HpN) demonstrating excellent catalytic activity towards benzoylacetonitrile was identified from a nitrilase tool-box, which was developed previously in our laboratory for (R)-o-chloromandelic acid synthesis from o-chloromandelonitrile. The HpN was overexpressed in Escherichia coli BL21 (DE3), purified to homogeneity by nickel column affinity chromatography, and its biochemical properties were studied. The HpN was very stable at 30–40?°C, and highly active over a wide range of pH values (pH 6.0–10.0). In addition, the HpN could tolerate against several hydrophilic organic solvents. Steady-state kinetics indicated that HpN was highly active towards benzoylacetonitrile, giving a KM of 4.2?mM and a kcat of 170?s?1, the latter of which is ca. fivefold higher than the highest record reported so far. A cascade reaction for the synthesis of optically pure (S)-β-phenylalanine from benzoylacetonitrile was developed by coupling HpN with an ω-transaminase from Polaromonas sp. JS666 in toluene-water biphasic reaction system using β-alanine as an amino donor. Various (S)-β-amino acids could be produced from benzoylacetonitrile derivatives with moderate to high conversions (73–99%) and excellent enantioselectivity (> 99% ee). These results are significantly advantageous over previous studies, indicating a great potential of this cascade reaction for the practical synthesis of (S)-β-phenylalanine in the future.
Preparation method of DL-mandelic acid
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Paragraph 0012-0017, (2018/04/02)
A preparation method of DL-mandelic acid comprises: using benzaldehyde, chloroform and sodium hydroxide as materials and beta-cyclodextrin as a catalyst, including the cyclodextrin via hydrophobic cavity structure that the beta-cyclodextrin has, forming d
