- Assessing and utilizing esterase specificity in antimicrobial prodrug development
-
As a class of enzymes, esterases have been investigated for decades and have found use in industrial processes, synthetic organic chemistry, and elsewhere. Esters are functional groups composed of an alcohol moiety and a carboxylic acid moiety. Although much work has explored the influence of the carboxyl moiety of an ester on its susceptibility to esterases, little work has explored the influence of the alcohol moiety. Here, we describe an in vitro methodology to explore the influence of changing the alcohol moiety of an ester on its enzymatic hydrolysis, including strategies for analyzing such data. We then describe leveraging data from these assays to develop targeted antimicrobial prodrugs that activate in certain species due to the discriminatory activity of species-specific esterases. We envisage the potential of genomics and machine learning to further these efforts. Finally, we anticipate the potential future uses of these ideas, including developing targeted anti-cancer compounds.
- Hetrick, Kenton J.,Raines, Ronald T.
-
-
- Method for efficiently preparing thiophene medical intermediates
-
The invention belongs to the field of synthesis of thiophene medical intermediates, discloses a method for efficiently preparing the thiophene medical intermediates, and particularly discloses a process for synthesizing 2-thiopheneacetic acid from 2-thiopheneethanol through a catalytic reaction, catalyzing the 2-thiopheneacetic acid to generate a 2-thiopheneacetyl chloride crude product and then purifying the 2-thiopheneacetyl chloride crude product. The reaction conditions are mild, the product purity is high, the synthesis efficiency is high, and the yield reaches 90% or above.
- -
-
Paragraph 0014; 0016; 0018
(2021/05/29)
-
- Synthesis method of 2-thiopheneacetic acid
-
The invention provides a synthesis method of 2-thiopheneacetic acid, which is characterized by comprising the following steps: (1) acylation reaction: carrying out Friedel-Crafts reaction on thiopheneand 2-chloroacetyl chloride as raw materials to obtain 2-chloroacetyl thiophene; and (2) rearrangement reaction: carrying out a Favanskii rearrangement reaction on the 2-chloroacetyl thiophene underan alkaline condition to obtain the 2-thiopheneacetic acid. The method is wide in raw material source, low in cost, few in steps, simple to operate, high in safety, small in pollution and easy to industrialize. Friedel-Crafts reaction and Favanskii rearrangement reaction are adopted, the conversion rate of the two reactions is high, the selectivity is good, the operation of the reaction process issimple, no special reagent is needed, the raw materials are cheap and easy to obtain, the requirement for equipment is not high, the product yield is high, few impurities are contained, and the method has remarkable advantages and practical value.
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Paragraph 0017; 0046; 0048-0049; 0051-0052; 0054
(2020/06/17)
-
- Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
-
A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
- Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
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p. 10913 - 10917
(2020/05/25)
-
- Preparation method of 2-thiopheneacetyl chloride
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The invention discloses a preparation method of 2-thiopheneacetyl chloride, and belongs to the technical field of chemical synthesis. The preparation method comprises the following steps: (1) dissolving 2-thiopheneethanol in an organic solvent, and reacting at 50-120 DEG C under the action of a solid acid catalyst, an alkali and an oxidant to prepare 2-thiopheneacetic acid, wherein the oxidant isoxygen or hydrogen peroxide; and (2) dissolving 2-thiopheneacetic acid in an organic solvent, and dropwise adding thionyl chloride to carry out an acylating chlorination reaction by taking an alkalineionic liquid as a catalyst so as to prepare 2-thiopheneacetyl chloride. The preparation method is simple in route, easy in obtaining of raw materials, mild in reaction conditions, and capable of realizing few byproducts and easy purification and separation due to adoption of oxygen or hydrogen peroxide as the oxidant in synthesis of 2-thiopheneacetic acid; and when the acylating chlorination reaction of 2-thiopheneacetic acid is carried out, the basic ionic liquid is adopted as the catalyst, the reaction process is stable and easy to control, the product yield is high, few byproducts are produced, so the method is an efficient and green synthesis process.
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Paragraph 0034-0037; 0041-0044; 0046-0049; 0051-0054; 0056
(2020/08/30)
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- Ni-Catalyzed β-Alkylation of Cyclopropanol-Derived Homoenolates
-
Metal homoenolates are valuable synthetic intermediates which provide access to β-functionalized ketones. In this report, we disclose a Ni-catalyzed β-alkylation reaction of cyclopropanol-derived homoenolates using redox-active N-hydroxyphthalimide (NHPI) esters as the alkylating reagents. The reaction is compatible with 1°, 2°, and 3° NHPI esters. Mechanistic studies imply radical activation of the NHPI ester and 2e β-carbon elimination occurring on the cyclopropanol.
- Mills, L. Reginald,Zhou, Cuihan,Fung, Emily,Rousseaux, Sophie A. L.
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supporting information
p. 8805 - 8809
(2019/11/03)
-
- Synthetic method of 2-thiopheneacetic acid
-
The invention discloses a synthetic method of 2-thiopheneacetic acid and belongs to the technical field of synthesis of intermediates. The synthetic method comprises the following steps: synthesis of3-(2-thiophene)-2,3-epoxy sodium propionate: taking 2-thiophenecarboxaldehyde and chloracetate as raw materials, carrying out Darzen reaction to synthesize epoxy acid ester and then hydrolyzing to obtain the 3-(2-thiophene)-2,3-epoxy sodium propionate; synthesis of 2-thiopheneacetic acid: acidizing the 3-(2-thiophene)-2,3-epoxy sodium propionate, carrying out decarboxylation rearrangement to obtain 2-thiophene acetaldehyde and then carrying out Pinnick oxidation reaction to obtain the 2-thiopheneacetic acid. In the synthesis method of the 2-thiopheneacetic acid provided by the invention, Darzen reaction and Pinnick oxidation reaction are adopted; due to high conversion rate of the Darzen reaction and good selectivity of Pinnick oxidation, the product has the advantages of high yield, fewercontained impurities, significant advantages and practical value.
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Paragraph 0027; 0030; 0031; 0034; 0035; 0038; 0039; 0042
(2019/07/29)
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- Design and evolution of an enzyme with a non-canonical organocatalytic mechanism
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The combination of computational design and laboratory evolution is a powerful and potentially versatile strategy for the development of enzymes with new functions1–4. However, the limited functionality presented by the genetic code restricts the range of catalytic mechanisms that are accessible in designed active sites. Inspired by mechanistic strategies from small-molecule organocatalysis5, here we report the generation of a hydrolytic enzyme that uses Nδ-methylhistidine as a non-canonical catalytic nucleophile. Histidine methylation is essential for catalytic function because it prevents the formation of unreactive acyl-enzyme intermediates, which has been a long-standing challenge when using canonical nucleophiles in enzyme design6–10. Enzyme performance was optimized using directed evolution protocols adapted to an expanded genetic code, affording a biocatalyst capable of accelerating ester hydrolysis with greater than 9,000-fold increased efficiency over free Nδ-methylhistidine in solution. Crystallographic snapshots along the evolutionary trajectory highlight the catalytic devices that are responsible for this increase in efficiency. Nδ-methylhistidine can be considered to be a genetically encodable surrogate of the widely employed nucleophilic catalyst dimethylaminopyridine11, and its use will create opportunities to design and engineer enzymes for a wealth of valuable chemical transformations.
- Burke, Ashleigh J.,Lovelock, Sarah L.,Frese, Amina,Crawshaw, Rebecca,Ortmayer, Mary,Dunstan, Mark,Levy, Colin,Green, Anthony P.
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p. 219 - 223
(2019/06/13)
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- Compounding method for 2-thiopheneacetyl chloride
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The invention discloses a compounding method for 2-thiopheneacetyl chloride and belongs to the technical field of organic synthesis. The 2-thiopheneacetyl chloride is compounded by taking thiophene asa raw material through following three-step reaction: 1) acquiring 2-thiophene acetate through the F-C reaction of thiophene and glycolate under the existence of catalyst; 2) hydrolyzing the 2-thiophene acetate under the existence of acid, thereby acquiring 2-thiopheneacetic acid; 3) treating the 2-thiopheneacetic acid in the manner of acylating chlorination with thionyl chloride under the catalysis of pyridine, thereby acquiring 2-thiopheneacetyl chloride. The compounding method for 2-thiopheneacetyl chloride has the characteristics of easily acquired raw materials and simple and convenientoperation and is suitable for industrial production.
- -
-
Paragraph 0042; 0045; 0046; 0084; 0085
(2019/01/06)
-
- Visible-Light-Driven External-Reductant-Free Cross-Electrophile Couplings of Tetraalkyl Ammonium Salts
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Cross-electrophile couplings between two electrophiles are powerful and economic methods to generate C-C bonds in the presence of stoichiometric external reductants. Herein, we report a novel strategy to realize the first external-reductant-free cross-electrophile coupling via visible-light photoredox catalysis. A variety of tetraalkyl ammonium salts, bearing primary, secondary, and tertiary C-N bonds, undergo selective couplings with aldehydes/ketone and CO2. Notably, the in situ generated byproduct, trimethylamine, is efficiently utilized as the electron donor. Moreover, this protocol exhibits mild reaction conditions, low catalyst loading, broad substrate scope, good functional group tolerance, and facile scalability. Mechanistic studies indicate that benzyl radicals and anions might be generated as the key intermediates via photocatalysis, providing a new direction for cross-electrophile couplings.
- Liao, Li-Li,Cao, Guang-Mei,Ye, Jian-Heng,Sun, Guo-Quan,Zhou, Wen-Jun,Gui, Yong-Yuan,Yan, Si-Shun,Shen, Guo,Yu, Da-Gang
-
p. 17338 - 17342
(2019/01/04)
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- Method for preparing acid through oxidating alcohols or aldehydes by oxygen
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The invention provides a method for preparing acid through oxidating alcohols or aldehydes by using oxygen or oxygen in air as an oxidant. The method comprises the steps: oxidating the alcohols or aldehydes to produce the acid at room temperature in an organic solvent in a manner of taking ferric nitrate (Fe(NO3)3.9H2O), 2,2,6,6-tetramethylpiperidyl nitrogen oxide (TEMPO) and an inorganic halide as catalysts and taking the oxygen or air as an oxidant, and oxidating diols to produce lactone; or, carrying out a reaction on the aldehydes, which serve as a raw material, under neutral conditions by taking ferric nitrate as a catalyst, and oxidating the aldehydes to produce the acid and peroxy acid. The method has the advantages that the method is environmentally friendly, the cost is low, the yield is high, the atomic economical efficiency is high, the compatibility of substrate functional groups is good, the reaction conditions are mild, a reaction scale can be enlarged, and the like, so that the method is suitable for being applied to industrial production.
- -
-
Paragraph 0051; 0052; 0053; 0054; 0073; 0074; 0075
(2017/09/29)
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- Green preparation technology of 2-thiopheneacetic acid
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The invention discloses a synthesis technology of 2-thiopheneacetic acid. The technology comprises the steps that 2-chloromethyl thiophene is taken as a raw material and reacts with acetone cyanohydrin in the presence of an organic solvent under the condition of a catalyst triethylamine to generate 2-thiopheneacetonitrile; 2-thiopheneacetonitrile is subjected to a series of reactions to generate 2-thiopheneacetic acid. The synthesis technology has the advantages that by selecting acetone cyanohydrin as a cyaniding reagent, usage of an extremely toxic substance sodium cyanide is avoided, the reaction yield is increased, the product quality is improved, the safety performance is relatively high, and industrialized production is promoted; the reaction conditions are mild, a little quantity of the catalyst is needed, and the processes are simple. Compared with an existing synthesis technology, the synthesis technology achieves the obvious economic benefits and environmental benefits.
- -
-
Paragraph 0006; 0013; 0014
(2017/08/28)
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- An industrial preparation method for 2-substituted-thiophene derivatives
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An industrial preparation method for 2-substituted-thiophene derivatives is provided. The method is characterized in that thiophene derivatives and nitroethylene are reacted to generate 2-(2-nitroethyl)-thiophene derivatives, the 2-(2-nitroethyl)-thiophene derivatives are oxidized to obtain 2-(2-carboxylic acid)-thiophene derivatives, and then the 2-ethylamine-thiophene derivatives can be obtained through reduction. The method is simple. Different from complex production manners and harsh production conditions in the prior art, synthesis of target products can be achieved by one step by the method. A production process and a synthesis route are optimized in the method, and therefore side reactions are less, after-treatment is convenient, and production conditions are mild in a production process, and the method is suitable for industrial production modes.
- -
-
Paragraph 0039; 0040; 0041
(2017/08/28)
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- A 2 - thiophene acetate clean production process of
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The invention relates to the chemical organic synthesis field and particularly discloses a method for preparing environment-friendly 2-thiopheneacetic acid with mild reaction condition. The 2-thiopheneacetic acid is prepared by taking 2, 2, 6, 6-tetramethyl piperidine nitrogen oxide (TEMPO) or the derivative as a catalyst and oxidizing 2-thiophene-ethanol through an oxidant such as sodium hypochlorite and sodium chlorite. The process is mild in reaction condition, high in reaction selectivity (95%), high in conversion rate (100%), high in yield (85%) and easy to be industrially operated.
- -
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Paragraph 0035-0069
(2017/08/25)
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- Iron Catalysis for Room-Temperature Aerobic Oxidation of Alcohols to Carboxylic Acids
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Oxidation from alcohols to carboxylic acids, a class of essential chemicals in daily life, academic laboratories, and industry, is a fundamental reaction, usually using at least a stoichiometric amount of an expensive and toxic oxidant. Here, an efficient and practical sustainable oxidation technology of alcohols to carboxylic acids using pure O2 or even O2 in air as the oxidant has been developed: utilizing a catalytic amount each of Fe(NO3)3·9H2O/TEMPO/MCl, a series of carboxylic acids were obtained from alcohols (also aldehydes) in high yields at room temperature. A 55 g-scale reaction was demonstrated using air. As a synthetic application, the first total synthesis of a naturally occurring allene, i.e., phlomic acid, was accomplished.
- Jiang, Xingguo,Zhang, Jiasheng,Ma, Shengming
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supporting information
p. 8344 - 8347
(2016/07/26)
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- DIARYL[A, G]QUINOLIZIDINE COMPOUND, PREPARATION METHOD THEREFOR, PHARMACEUTICAL COMPOSITION, AND USES THEREOF
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The present invention relates to a diarylo[a,g]quinolizidine compound of formula (I), enantiomer, diastereoisomer, racemate, mixture, pharmaceutically acceptable salt, crystalline hydrate or solvate thereof; the preparation method thereof, and uses thereof in preparing an experimental model drugs related to dopamine receptors and 5-HT receptors or a medicament for treating or preventing a disease related to dopamine receptors and 5-HT receptors.
- -
-
Paragraph 0243; 0244
(2015/03/28)
-
- DIARYL[A, G]QUINOLIZIDINE COMPOUND, PREPARATION METHOD THEREFOR, PHARMACEUTICAL COMPOSITION, AND USES THEREOF
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The present invention relates to a diarylo[a,g]quinolizidine compound of formula (I), enantiomer, diastereoisomer, racemate, mixture, pharmaceutically acceptable salt, crystalline hydrate or solvate thereof; the preparation method thereof, and uses thereof in preparing an experimental model drugs related to dopamine receptors and 5-HT receptors or a medicament for treating or preventing a disease related to dopamine receptors and 5-HT receptors.
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Paragraph 0303; 0304
(2015/05/26)
-
- General and practical conversion of aldehydes to homologated carboxylic acids
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(Chemical Equation Presented) The reaction of aldehydes with trichloromethide followed by sodium borohydride or sodium phenylseleno(triethyl) borate under basic conditions affords homologated carboxylic acids in high yields. This operationally simple procedure provides a practical, efficient alternative to other homologation protocols. The approach is compatible with sensitive aldehydes including enals and enolizable aldehydes. It also offers convenient access to α-monodeuterated carboxylic acids.
- Cafiero, Lauren R.,Snowden, Timothy S.
-
supporting information; experimental part
p. 3853 - 3856
(2009/07/01)
-
- Lactam metalloprotease inhibitors
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The present application describes novel lactams and derivatives thereof of formula I: or pharmaceutically acceptable salt forms thereof, wherein rings ring B is a 4-8 membered cyclic amide containing from 0-3 additional heteroatoms selected from N, O, and S, which are useful as metalloprotease inhibitors.
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- Quinolones as gonadotropin releasing hormone (GnRH) antagonists: Simultaneous optimization of the C(3)-aryl and C(6)-substituents
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A series of 3-arylquinolones was prepared and evaluated for their ability to act as gonadotropin releasing hormone (GnRH) antagonists. A variety of substitution patterns of the 3-aryl substituent are described. The 3,4,5-trimethylphenyl substituent (23h) was found to be optimal. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Young, Jonathan R.,Huang, Song X.,Chen, Irene,Walsh, Thomas F.,DeVita, Robert J.,Wyvratt Jr., Matthew J.,Goulet, Mark T.,Ren, Ning,Lo, Jane,Yang, Yi Tien,Yudkovitz, Joel B.,Cheng, Kang,Smith, Roy G.
-
p. 1723 - 1727
(2007/10/03)
-
- Direct Carbonylation of Benzyl Alcohol and Its Analogs Catalyzed by Palladium and HI in Aqueous Systems and Mechanistic Studies
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Carbonylation of benzyl alcohol, benzyl formate, dibenzyl ether, and benzyl phenylacetate catalyzed by palladium complexes and promoted by hydrogen iodide gives phenylacetic acid in moderate to excellent yields in aqueous systems. Application of the carbonylation process to other arylmethanol analogs provides convenient means to prepare 2-naphthaleneacetic acid, 3-isochromanone, 1,4-benzenediacetic acid, and o-hydroxybenzeneacetic acid. A mechanism for the catalytic reaction is proposed, which involves (1) formation of benzyl iodide by the reaction of benzyl alcohol with HI in situ, (2) oxidative addition of benzyl iodide to palladium(0) to form a benzylpalladium iodide species. (3) CO insertion into the Pd-benzyl bond to form a (phenylacetyl)palladium iodide species. (4) reductive elimination of phenylacetyl iodide, and (5) its hydrolysis into phenylacetic acid. Evidence supporting the mechanism was obtained by examining the properties of benzyl- and (phenylacetyl)palladium iodide and chloride complexes. Formation of benzyl(carbonyl)palladium species and migratory insertion of the benzyl group to CO was confirmed by means of NMR at low temperature under high pressure.
- Lin, Yong-Shou,Yamamoto, Akio
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p. 723 - 734
(2007/10/03)
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- Oxidative decarbonylation of β-arylpyruvic acids using sodium perborate
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Oxidation of β-aryl- and β-heteroarylpyruvic acids using sodium perborate tetrahydrate (SPB) in aqueous solution at ambient temperature gives the corresponding arylacetic acids in good yield (68-86%). The mild conditions are convenient for the preparation of thermally unstable acids. In particular the method has been applied to the preparation of an unstable 5- nitroimidazol-2-yl ethanoic acid which could not be obtained using other reagents apparently due to enolisation of the pyruvic acid precursor. Attempts to achieve decarbonylation using calcium hypochlorite or SPB in acidic solution lead to the 2 chloromethyl derivatives. The novel 5- nitroimidazol-2-yl ethanoic acid, which was required as a precursor of molecules of biological interest, has been fully characterised and converted to a known amide. Reaction of this acid with Vilsmeier's reagent gave an enamine derivative and not the expected vinamidinium salt. This novel mode of reaction is attributable to intramolecular hydrogen-bonding and favourable conjugation.
- Morrow, Nicholas,Ramsden, Christopher A.,Sargent, Bruce J.,Wallett, Christiaan D.
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p. 9603 - 9612
(2007/10/03)
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- N-acyl sulfamic acid esters (or thioesters), N-acyl sulfonamides, and N-sulfonyl carbamic acid esters (or thioesters) as hypercholesterolemic agents
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The present invention is directed to compounds useful for the regulation of cholesterol of Formula I, methods for using them and pharmaceutical compositions thereof, STR1 wherein X and Y are oxygen, sulfur, or (CR'R")n wherein n is 1 to 4; R is hydrogen, alkyl, or benzyl; R1 and R2 are phenyl, substituted phenyl, naphthyl, substituted naphthyl, an aralkyl group, an alkyl chain, adamantyl, or a cycloalkyl group.
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- Triazolo-pyrimidine intermediates
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There are disclosed a β-lactam compound represented by the formula (I): STR1 wherein R1 represents an acyl group; M represents a hydrogen atom, a protective group of an eliminatable group which is easily hydrolyzable in a human body; B represents a group represented by the formula (b): STR2 where at least one of R2, R3 and R9 represent a group represented by the formula: -A-OR4 where R4 represents a hydrogen or a lower alkyl group; and A represents a straight or branched alkylene group having 1 to 6 carbon atoms; and a remaining group or groups are each independently a hydrogen atom; a cyano group; a lower alkyl group which may be substituted by a halogen atom; a carbamoyl group which may be substituted by a lower alkyl group; a cycloalkyl group; or a carboxyl group which may be substituted by a protective group of an eliminatable group which is easily hydrolyzable in a human body, and also when R9 is -A-OR4, R2 and R3 may be combined with each other to form an alkylene group having 3 to 4 carbon atoms; and Z represents a nitrogen atom or a group represented by the formula: C-R10 where R10 represents a hydrogen atom, a carboxyl group or a lower alkyl group which may be substituted by a hydroxy group or a lower alkoxy group, or its pharmaceutically acceptable salt, and a process for preparing the same, an intermediate for synthesis of the same and a medicinal composition for bacterially infectious disease therapy containing the same.
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- GAS-PHASE REPLACEMENT ?0 SUBSTITUENT CONSTANTS OF HETEROARYL GROUPS
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Hammett replacement ?0 substituent constants of pyridyl, thienyl, and furyl groups are reported for the first time from gas-phase eliminations of their t-butyl and isopropyl heteroarylcarboxylate esters.
- Al-Awadi, Nouria A.,Al-Bashir, Rasha F.,ElDusouqui, Osman M. E.
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p. 1699 - 1702
(2007/10/02)
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- Oxidative Rearrangement of Alkynes to Carboxylic Acid Esters by benzene in Methanol
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A direct synthesis of methyl aryl alkanoate via oxidative rearrangement of alkynes using benzene in methanol is described.
- Moriarty, Robert M.,Vaid, Radhe K.,Duncan, Michael P.,Vaid, Beena K.
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p. 2845 - 2848
(2007/10/02)
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- Process for preparation of alkanoic acids
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A process for preparation of substituted acetic acids having the general formula I: in which R is selected from the group consisting in one hydrogen atom and C1 -C4 -alkyl radicals, and Ar is selected from the group consisting in radicals of aromatic nature selected from the following radicals: 2-thienyl, 2-methoxy-1-naphthyl, 3,4-methylenedioxy-phenyl, and the substituted phenyls of the general formula II: STR1 where R1 is selected from the group consisting in hydrogen and C1 -C4 -alkyl groups, and R2 is selected from the group consisting in hydrogen, halogen, alkyl, alkoxy and hydroxy-groups, such process comprising the step of reacting under heat in an acid medium, in the presence of red phosphorus and catalytic quantities of iodine or hydriodic acid, an alpha carbonylated carboxylic acid having the general formula III: in which R has the same meaning as above with an unsaturated derivative of aromatic nature selected from the group consisting in thiophene, 2-methoxynaphthalene, 1,2-methylenedioxy-benzene, and the substituted aromatic hydrocarbons having the general formula IV: STR2 in which R1, R2 have the same meanings as above, possibly within a compatible organic solvent.
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- Process for preparing alpha-thienylacetic acid, esters and salts thereof
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A process is disclosed for preparing alpha-thienylacetic acid, alkyl esters and salts thereof by carbonylation of 2-chloromethylthiophene, characterized in that 2-chloromethylthiophene and carbon monoxide are reacted under atmospheric pressure and at a temperature ranging from 0° to 60° C., in an aqueous-alcoholic solution in the presence of a catalyst selected from the class consisting of Co2 (CO)8, MCo(CO)4 where M is selected from the class consisting of Na and K, and a system comprising a cobalt salt (such as cobaltous chloride), a ferro-manganese alloy and at least one sulphur-containing promoter (such as the alkaline sulphides and thiosulphates), and in the presence of an inorganic base, and the separating the alpha-thienylacetic acid from the resulting salt and/or ester obtained.
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- Process for preparing aromatic acetic acid
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There are disclosed processes for preparing an aromatic acetic acid by the reaction of an aromatic aldehyde with a combination of a trihalomethane and an alkanethiol, and by the reaction of an alcohol derivative (2,2,2-trihalo-1-arylethanol) with an alkanethiol, in the presence of a base in a mixed medium of water and an aprotic polar solvent.
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- Process for preparing thiophene derivatives
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Process for the preparation of a series of thiophene derivatives, from which 2-thiopheneacetic acid derivatives can easily be prepared, in high yields and selectivity by using substituted or unsubstituted 2-acetylthiophenes as the starting materials by easy operations. 2-Thiopheneacetic acid derivatives are very useful compounds as the chemical modifier of penicillin and cephalosporin. In the course of the reaction, 2-(dihaloacetyl)thiophenes are formed which are valuable intermediates for the production of not only 2-thiopheneacetic acids but also thioprofenic acid which is known as an anti-inflammatory agent.
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- Process for preparing thiophene derivatives and thiophene derivatives obtained thereby
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Process for the preparation of a series of thiophene derivatives, from which 2-thiopheneacetic acid derivatives can easily be prepared, in high yields and selectivity by using substituted or unsubstituted thiophenes as the starting materials by easy operations. 2-Thiopheneacetic acid derivatives are very useful compounds as the chemical modifier of penicillin and cephalosporin. Novel compounds, i.e. α-arylthio-2-thiopheneacetic acids are also disclosed. These compounds are useful as the intermediates of the synthesis of 2-thiopheneacetic acids.
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- Method for preparing thienylacetic acids
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A method for preparing thienylacetic acid and its derivatives is disclosed, wherein a glyoxylic ester is made to react with hydrazine, and after with potash. Advantageously, the glyoxylic ester is prepared by condensation of a monoester monochloride of oxalic acid upon a thiophenic derivative, in the presence of titanium chloride. The so obtained products are useful as organic synthesis intermediaries for various products of pharmaceutical type.
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- Thiophene derivatives and process for preparation thereof
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Commercially advantageous processes for preparing thienylacetic acid, furylacetic acid or alkyl esters of these. Novel thiophene or furan derivatives that can be used as starting materials for preparing the above compounds. Processes for preparing these starting materials are also provided.
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