- Preparation method of carboxylic ester compound
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The invention relates to a preparation method of a carboxylic ester compound, which comprises the following steps: reacting carboxylic acid with methanol in air under the catalysis of nitrite to obtain an ester compound, the preparation method disclosed by the invention has the advantages of rich raw material sources, cheap and easily available catalyst, mild reaction conditions, simplicity and convenience in operation and the like, a series of fatty carboxylic acids can be modified with high yield, and particularly, the traditional esterification method is generally not suitable for esterification of drug molecules. By utilizing the method, a series of known drug molecules can be modified, so that a shortcut is provided for discovering new drug molecules.
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Paragraph 0065-0066
(2021/03/30)
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- Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
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In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
- Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
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supporting information
p. 2713 - 2718
(2021/06/25)
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- Lewis-base-catalysed selective reductions of ynones with a mild hydride donor
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Ynones are efficiently reduced with a mild hydride donor in the presence of a catalytic amount of nucleophilic phosphines. The reactions are selective 1,2-reductions that give propargyl alcohols in yields of up to 96%. It is proposed that success in these reactions depends on the activation of ynones by a Lewis base catalyst. A protic additive plays a key role in suppressing the undesired reaction pathways and accelerating the 1,2-reductions.
- Sch?mberg,Zi,Vilotijevic
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supporting information
p. 3266 - 3269
(2018/04/05)
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- A phenoxy carboxylic acid ester herbicide preparation method (by machine translation)
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The invention provides a phenoxy carboxylic acid ester herbicide preparation method, including: S1, phenol in the presence of alkaline substance with the chlorinated carboxylic acid ester condensation reaction, phenoxy carboxylic acid ester obtained; the ClR states the chloro- carboxylic acid ester of the general formula1 COOR, R1 Is C1 - 3 alkylene or alkylidene, R is C1 - 10 alkyl or C3 - 10 cycloalkyl; S2, the [...] ester in the 1st and 2nd catalyst the presence of a catalyst, with the chlorinating agent to carry out the selective chlorination of, get [...] ester; the Lewis acid catalyst is selected from the 1st, the 2nd catalyst is C5 - 22 of the thioether, thiazole, thiophene compounds or different benzisothiazoles; S3, will the [...] ester with an alcohol reaction, as shown in formula I phenoxy carboxylic acid ester herbicide; R3 Is H, Cl or CH3 , R ' is a C4 - 20 alkyl or cycloalkyl. This invention can improve the product quality and the production environment, three waste low. (by machine translation)
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Paragraph 0086; 0087; 0090; 0091
(2019/01/08)
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- Aerobic Copper-Catalyzed O-Methylation with Methylboronic Acid
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The oxidative coupling of alkylboronic acids with oxygen nucleophiles offers a strategy for replacing toxic, electrophilic alkylating reagents. Although the Chan-Lam reaction has been widely applied in the arylation of heteroatom nucleophiles, O-alkylation with boronic acids is rare. We report a Cu-catalyzed nondecarboxylative methylation of carboxylic acids with methylboronic acid that proceeds in air with no additional oxidant. An isotope-labeling study supports an oxidative cross-coupling mechanism, in analogy to that proposed for Chan-Lam arylation.
- Jacobson, Clare E.,Martinez-Mu?oz, Noelia,Gorin, David J.
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p. 7305 - 7310
(2015/07/28)
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- Synthesis and biological evaluation of phenoxyacetic acid derivatives as novel free fatty acid receptor 1 agonists
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Free fatty acid receptor 1 (FFA1) is a new potential drug target for the treatment of type 2 diabetes because of its role in amplifying glucose-stimulated insulin secretion in pancreatic β-cell. In the present studies, we identified phenoxyacetic acid derivative (18b) as a potent FFA1 agonist (EC50 = 62.3 nM) based on the structure of phenylpropanoic acid derivative 4p. Moreover, compound 18b could significantly improve oral glucose tolerance in ICR mice and dose-dependently reduced glucose levels in type 2 diabetic C57BL/6 mice without observation of hypoglycemic side effect. Additionally, compound 18b exhibited acceptable PK profiles. In summary, compound 18b with ideal PK profiles exhibited good activity in vitro and in vivo, and might be a promising drug candidate for the treatment of diabetes mellitus.
- Wang, Xuekun,Zhao, Tianxiao,Yang, Baowei,Li, Zheng,Cui, Jian,Dai, Yuxuan,Qiu, Qianqian,Qiang, Hao,Huang, Wenlong,Qian, Hai
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p. 132 - 140
(2015/02/18)
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- Switched enantiopreference of Humicola lipase for 2-phenoxyalkanoic acid ester homologs can be rationalized by different substrate binding modes
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Humicola lanuginosa lipase was used for enantioselective hydrolyses of a series of homologous 2-phenoxyalkanoic acid ethyl esters. The enantioselectivity (E-value) of the enzyme changed from an (R)-enantiomer preference for the smallest substrate, 2-pheno
- Berglund, Per,Vallikivi, Imre,Fransson, Linda,Dannacher, Heinz,Holmquist, Mats,Martinelle, Mats,Bjoerkling, Fredrik,Parve, Omar,Hult, Karl
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p. 4191 - 4202
(2007/10/03)
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- The use of dialkyl carbonates for safe and highly selective alkylations of methylene-active compounds. A process without waste production
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The non-toxic compound dimethyl carbonate (DMC) can be used as a methylating and a methoxycarbonylating agent in place of methyl chloride and phosgene, respectively. We report here that DMC and other dialkyl carbonates (DAlkCs: dimethyl, diethyl and dibenzyl carbonates) allow very selective alkylations of a variety of CH2-acidic compounds. Both arylacetonitriles and alkyl arylacetates react with DAIkCs to yield the mono-C-alkylated derivatives (α-alkyl-α-arylacetonitriles and alkyl α-alkyl-α-arylacetates) with a selectivity of up to 99%, at complete conversion. Likewise, the mono-C-methylation by DMC proceeds selectively also on (aryloxy)acetonitriles and methyl (aryloxy)acetates. The reactions are carried out at temperature of 180-220°C in the presence of weak bases (usually K2CO3); under such conditions, DAlkCs efficiently replace the common and very toxic alkylating agents (dialkyl sulfates and alkyl halides). In addition to the high selectivity obtained and the intrinsic safety of the dialkyl carbonates, the reported reactions give rise to neither organic nor inorganic waste products.
- Bomben, Andrea,Selva, Maurizio,Tundo, Pietro
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p. 256 - 260
(2007/10/03)
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- A new synthesis of 2-aryloxypropionic acids derivatives via selective mono-C-methylation of methyl aryloxyacetates and aryloxyacetonitriles with dimethyl carbonate
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A one-pot procedure for the mono-C-methylation of methyl aryloxyacetates and aryloxyaceto nitriles by dimethyl carbonate (DMC) is reported. The reaction is carried out in an autoclave at high temperatures (180-200°C) and in the presence of a base (K2
- Bomben, Andrea,Marques, Carlos A.,Selva, Maurizio,Tundo, Pietro
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p. 11573 - 11580
(2007/10/02)
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- Optical resolution of aryloxypropionic acids and their esters by HPLC on cellulose tris-3,5-dimethyl-triphenylcarbamate derivative
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Chiral chromatographic resolution of a series of antiphlogistic 2- aryloxypropionic acids and their methyl and ethyl esters was performed using a Chiralcel OD column. The CSP selected resolved most of the acids and esters efficiently, the enantiomers being well separated without requiring time consuming analysis. Chromatographic separation of R enriched samples was performed to determine the correct elution order. Using eluting systems such as hexane and 2-propanol, or hexane, 2-propanol and formic acid, the S enantiomer of all acids and esters was always found to elute first. We also considered the role of electron-donating or electron-withdrawing substituents (at the aryloxylic moiety) on the chiral resolution. It was shown that the electronic features of the substituents have more influence on the chiral interactions between the solutes and the CSP than their steric hindrance. Finally we determined, by molecular models, the interaction between CSP and solutes. In this way were able to determine all the potential sites for interactions, which are compatible with the conformations of the compounds and the structure of the stationary phase, and point out those interactions which enable chiral resolution.
- Azzolina,Collina,Ghislandi
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p. 1401 - 1416
(2007/10/02)
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- A NEW CHIRAL HOST COMPOUND 10,10'-DIHYDROXY-9,9'-BIPHENANTHRYL. OPTICAL RESOLUTION OF PROPIONIC ACID DERIVATIVES, BUTYRIC ACID DERIVATIVES, AND 4-HYDROXYCYCLOPENT-2-EN-1-ONE DERIVATIVES BY COMPLEXATION
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Optically active 10,10'-dihydroxy-9,9'-biphenanthryl was designed as a new chiral host compound for optical resolution of guest compounds, and was found to be wery effective for resolution of the title guest compounds.
- Toda, Fumio,Tanaka, Koichi
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p. 1807 - 1810
(2007/10/02)
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- Enzyme catalysed hydrolysis of chlorophenoxypropionates
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We report on the enzymatic hydrolysis of methyl 2-phenoxypropionate and of the following chlorinated derivatives: methyl o-chloro-, m-chloro-, p-chloro-, and o,p-dichloro-2-phenoxypropionates. α-Chymotripsyn, lipase, and pig liver esterase have an R enantioselectivity whereas subtilisin has an S enantioselectivity.Enantiomeric excess (e.e.) cover a wide range (from 5 to 100percent).
- Chenevert, Robert,D'Astous, Linda
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p. 1219 - 1222
(2007/10/02)
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- Resolution of racemic mixtures of aliphatic acid esters
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Racemic mixtures of partially water-soluble esters defined by the formula STR1 wherein R and R1 represent hydrogen and C1 -C4 alkyl; R2 represents C1 -C4 alkyl and X represents halogen, aliphatic or aromatic groups and substituted derivatives thereof wherein R, R1 and X are different can be resolved by reducing the water solubility of a racemic mixture of said esters by means other than changing the chemical composition of the ester, contacting the racemic mixture of esters of reduced water solubility with a lipase enzyme from Candida cylindracea capable of stereospecifically resolving the racemic mixture of hydrolysis and stereospecifically resolving the racemic mixture.
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