Ethyl Thioglycolate Research Articles

Water mediated redox-neutral cleavage of arylalkenes via photoredox catalysis

Cleavage of carbon-carbon bonds remains a challenging task in organic synthesis. Traditional methods for splitting Csp2=Csp2 bonds into two halves typically involve non-redox (metathesis) or oxidative (ozonolysis) mechanisms, limiting their synthetic potential. Disproportionative deconstruction of alkenes, which yields one reduced and one oxidized fragment, remains an unexplored area. In this study, we introduce a redox-neutral approach for deleting a Csp2 carbon unit from substituted arylalkenes, resulting in the formation of an arene (reduction) and a carbonyl product (oxidation). This transformation is believed to proceed through a mechanistic sequence involving visible-light-promoted anti-Markovnikov hydration, followed by photoredox cleavage of Csp3-Csp3 bond in the alcohol intermediate. A crucial consideration in this design is addressing the compatibility between the highly reactive oxy radical species in the latter step and the required hydrogen-atom-transfer (HAT) reagent for both steps. We found that ethyl thioglycolate serves as the optimal hydrogen-atom shuttle, offering remarkable chemoselectivity among multiple potential HAT events in this transformation. By using D2O, we successfully prepared dideuteromethylated (-CD2H) arenes with good heavy atom enrichment. This work presents a redox-neutral alternative for alkene deconstruction, with considerable potential in late-stage modification of complex molecules.

An Ethyl-Thioglycolate-Functionalized Fe3O4@ZnS Magnetic Fluorescent Nanoprobe for the Detection of Ag+ and Its Applications in Real Water Solutions.

Ethyl-thioglycolate-modified Fe3O4@ZnS nanoparticles (Fe3O4@ZnS-SH) were successfully prepared using a simple chemical precipitation method. The introduction of ethyl thioglycolate better regulated the surface distribution of ZnS, which can act as a recognition group and can cause a considerable quenching of the fluorescence intensity of the magnetic fluorescent nanoprobe, Fe3O4@ZnS-SH. Benefiting from stable fluorescence emission, the magnetic fluorescent nanoprobe showed a highly selective fluorescent response to Ag+ in the range of 0-400 μM, with a low detection limit of 0.20 μM. The magnetic fluorescent nanoprobe was used to determine the content of Ag+ in real samples. A simple and environmentally friendly approach was proposed to simultaneously achieve the enrichment, detection, and separation of Ag+ and the magnetic fluorescent nanoprobe from an aqueous solution. These results may lead to a wider range of application prospects of Fe3O4 nanomaterials as base materials for fluorescence detection in the environment.

Study on flotation behavior and mechanism of separating chalcopyrite and Molybdenite with ethyl mercaptoglycolate as inhibitor

The effect of ethyl thioglycolate organic small molecule inhibitors on chalcopyrite molybdenite flotation behaviour is investigated via single mineral micro-flotation tests, zeta potential tests, and X-ray photoelectron spectroscopy (XPS) analysis. Results of the flotation test indicate that ethyl thioglycolate organic small-molecule inhibitors can effectively separate Cu and Mo and selectively inhibit chalcopyrite under weak alkaline conditions. Infrared spectroscopy and XPS analysis show that hydrophilic functional groups C=O and -COOH in the ethyl thioglycolate organic small molecules can chemically adsorb onto the chalcopyrite surface. Moreover, ethyl thioglycolate has no obvious effect on zeta potential of molybdenite. Therefore, ethyl thioglycolate can effectively separate chalcopyrite and molybdenite.

Green separation and recovery of molybdenum from tungstate solution achieved by using a recyclable vulcanizing agent

Separation of molybdenum (Mo) from tungstate solution has become a bottleneck issue in tungsten (W) metallurgy and did hinder the development of high purity tungsten materials. The traditional Mo removal methods using Na2S, NaHS as vulcanizing reagent are suffering the environmental issues of toxic H2S gas and molybdenum trisulfide (MoS3) sludge. To achieve the green separation of Mo from tungstate, a recycle vulcanizing reagent, ethyl thioglycolate (ET) was introduced for the vulcanization of molybdate (MoO42−) from tungstate solution. The vulcanization of Mo by ET, the selective extraction of vulcanized MoO42− from tungstate and the recycling of ET were systematically investigated. The results demonstrated that a high vulcanization efficiency of >98% for MoO42− was achieved and more than 97% of Mo was removed and recovered via vulcanization followed by single-stage solvent extraction, producing a purified tungstate solution with Mo < 5 mg/L (Mo/WO3 < 1 × 10−4) and a byproduct of molybdate solution with 4.1 g/L Mo and <0.01 g/L WO3 under optimal conditions. Additionally, ET exhibited an ideal cycling performance, the regeneration efficiency and the recycled vulcanization efficiency were >95% and >98%, respectively. Compared with traditional vulcanizing reagents, introduction of ET eliminates the emission of toxic H2S gas, significantly decreases the cost caused by the unrecyclable reagent, and transferred the MoS3 sludge into a valuable crude Mo byproduct, which provides an alternative for the green separation and recovery of Mo from tungstate.

Synthesis of thieno[2,3-b]pyrrole-2(4)-carboxylic and 2,4-dicarboxylic acids

1-Substituted 5-chloro-4-formylpyrrole-3-carboxylates reacted with thioglycolic acid or ethyl thioglycolate in EtOH containing EtONa at room temperature, forming 4-(ethoxycarbonyl)thieno[2,3-b]pyrrole-2-carboxylic acids or thieno[2,3-b]pyrrole-2,4-dicarboxylates. Cyclocondensation with thioglycolic acid upon refluxing in K2CO3–DMF system was accompanied by decarboxylation and led to the formation of thieno[2,3-b]pyrrole-4-carboxylates. Hydrolysis of the obtained carboxylates with LiOH provided thieno[2,3-b]pyrrole-2(4)-carboxylic and 2,4-dicarboxylic acids.

NEW APPROACH TO THE SYNTHESIS OF 2,2':5',2''-TERTHIOPHENE-5,5''- AND 2,2':5',2'':5'',2'''-QUATERTHIOPHENE-5,5'''-DICARBOXYLIC ACIDS

The reaction of bromosuccinimide with esters of 3-substituted 2,2'-bithiophene-5-carboxylic acids was used to obtain their 5'-bromo derivatives, which were further converted to esters of 3,3'''-disubstituted 2,2':5',2'':5'',2'''-quaterthiophene-5,5'''-dicarboxylic acids by heating in DMF with catalytic amounts of Pd(PPh 3 ) 4 . Ester of 3-decyl-2,2'-bithiophene-5-carboxylic acid was acylated at the С-5' position with lauroyl chloride in the presence of SnCl 4 , producing the respective ketone that was used in Vilsmeier–Haack reaction (DMF, POCl 3 ). The 3-chloroacrylaldehyde derivative that was thus obtained was further used in reaction with ethyl thioglycolate in the presence of sodium ethoxide, giving ester of 3,3''-decyl-2,2':5',2''-terthiophene-5,5''-dicarboxylic acid. Alkaline hydrolysis of the obtained esters led to the corresponding 2,2':5',2'':5'',2'''-quaterthiophene-5,5'''- and 2,2':5',2''-terthiophene-5,5''-dicarboxylic acids. Authors: Anastasia S. Kostyuchenko, Evgeny B. Ulyankin, Anton L. Shatsauskas, Vladislav Yu. Shuvalov, Alexander S. Fisyuk*

Synthesis, Modeling Study and Antioxidants Activity of New Heterocycles Derived from 4-Antipyrinyl-2-Chloroacetamidothiazoles

The present work reports the preparation of twelve new heterocyclic scaffolds containing an antipyrinyl-thiazole hybrid through the reaction of 4-antipyrinyl-2-chloroacetamido-thiazoles 1 and 6 with various types of nucleophiles, namely; ethyl thioglycolate, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, ammonium thiocyanate, malononitrile, and salicylaldehyde. The constructed compounds were characterized by conventional spectroscopic techniques (IR, 1H NMR, 13C NMR, and mass analysis). A DFT method (material studio package) was used to predict the geometry, bond lengths, bond angles, and dipole moments as well as other global chemical reactivities of the constructed antipyrinyl-thiazole compounds. Also, their semi-core pseudopods calculations (dspp) were carried out with DNP (double numerical basis sets plus polarization functional) to predict the properties of materials. In addition, the antioxidant activity of these antipyrinyl-thiazole scaffolds has been screened by the ABTS method. The results indicated that 2-(4-antipyrinylthiazolylamino)-5-substituitedbenzylidene-thiazol-4(5H)-ones 10b and 10c exhibited the best antioxidant activity with a percentage inhibition of 85.74% and 83.51%, respectively.

New approach to the synthesis of 2,2':5',2''-terthiophene-5,5''-and 2,2':5',2'':5'',2'''-quaterthiophene-5,5'''-dicarboxylic acids

The reaction of bromosuccinimide with esters of 3-substituted 2,2'-bithiophene-5-carboxylic acids was used to obtain their 5'-bromo derivatives, which were further converted to esters of 3,3'''-disubstituted 2,2':5',2'':5'',2'''-quaterthiophene-5,5'''-dicarboxylic acids by heating in DMF with catalytic amounts of Pd(PPh3)4. Ester of 3-decyl-2,2'-bithiophene-5-carboxylic acid was acylated at the С-5' position with lauroyl chloride in the presence of SnCl4, producing the respective ketone that was used in Vilsmeier–Haack reaction (DMF, POCl3). The 3-chloroacrylaldehyde derivative that was thus obtained was further used in reaction with ethyl thioglycolate in the presence of sodium ethoxide, giving ester of 3,3''-decyl-2,2':5',2''-terthiophene-5,5''-dicarboxylic acid. Alkaline hydrolysis of the obtained esters led to the corresponding 2,2':5',2'':5'',2'''-quaterthiophene-5,5'''- and 2,2':5',2''-terthiophene-5,5''-dicarboxylic acids.

Influence of Hydrogen-Bonding Interactions on Nuclearity and Structure of Palladium Tiara-like Complexes.

The role of intramolecular hydrogen-bonding interactions upon the nuclearity of palladium tiara-like complexes is reported herein. The synthesis of three palladium tiaras is described with three related thiolate ligands that vary in their hydrogen-bonding capability, amide vs ester for N-acetylcysteamine (tiara 1) vs 2-mercaptoethyl acetate (tiara 2) or ethyl thioglycolate (tiara 3), and in the relative position of the ester group, 2-mercaptoethyl acetate (2) or ethyl thioglycolate (3). Mass spectrometry indicates that, in the absence of protic solvents, N-acetylcysteamine reacts to form exclusively a six-membered tiara, [Pd(SCH2CH2NHCOCH3)2]6, 1, whereas the ester containing analogues form both six- and eight-membered tiaras. Single-crystal X-ray diffraction studies indicate the significance of intramolecular N–H···O hydrogen bonds in determining the nuclearity of the amide-containing tiara 1. NMR studies indicate that 1 is not in equilibrium with larger tiaras in solution, and that the smaller size of the aggregate inhibits the fluxional behavior of the pendant thiolate ligands, typically observed for larger tiaras. Electrochemical investigations of 1 reveal reductive processes that exhibit an increase in current upon addition of acid, along with the formation of palladium nanoparticles.

ChemInform Abstract: Base Catalyzed Reaction of Ethyl Thioglycolate with β‐Aryl‐β‐(methylthio) Acroleins: A General Method for the Synthesis of 2‐Carbethoxy‐5‐substituted/4,5‐Annulated Thiophenes in High Overall Yields.

(Methylthio) acroleins 1a–m were shown to be stable unlike their counterpart the chloroacroleins and their efficacy as 1,3-dielectrophilic properties have now been examined successfully in this work. They are shown to react with ethyl thioglycolate in the presence of anhydrous potassium carbonate in boiling ethanol to yield the corresponding 5-substituted/4,5-annulated-2-carbethoxy thiophenes in 70–80% overall high yields.

Base catalyzed reaction of ethyl thioglycolate with β-aryl-β-(methylthio) acroleins: a general method for the synthesis of 2-carbethoxy-5-substituted/4,5-annulated thiophenes in high overall yields

(Methylthio) acroleins 1a–m were shown to be stable unlike their counterpart the chloroacroleins and their efficacy as 1,3-dielectrophilic properties have now been examined successfully in this work. They are shown to react with ethyl thioglycolate in the presence of anhydrous potassium carbonate in boiling ethanol to yield the corresponding 5-substituted/4,5-annulated-2-carbethoxy thiophenes in 70–80% overall high yields.

An efficient, one-pot three-component synthesis of 4H-thiazolo[3,2-a][1,3,5]triazin-6-one derivatives

Abstract A simple and efficient protocol was established to synthesize thiazolo[3,2-a][1,3,5]triazin-6-ones via three-component one-pot condensation reaction of readily available thioglycolic acid or ethyl thioglycolate, aldehydes or ketones and dicyandiamide in the presence of ammonium acetate. All of the newly synthesized compounds were characterized by spectroscopic analyses.

Synthesis and antimicrobial activity of new heterocyclic compounds containing thieno[3,2-c]coumarin and pyrazolo[4,3-c]coumarin frameworks

Reaction of 4-chlorocoumarin-3-carbonitrile with ethyl thioglycolate and ethyl glycinate hydrochloride leads to a series of title products. Hydrazinolysis of amino thienocoumarin carboxylate afforded the hydrazine derivative which underwent various reactions to build new heterocyclic rings containing thienocoumarin moiety. Chloro acetylation of aminoester compound afforded the chloro acetyl amino which underwent nucleophilic substitution reactions various amines. The following treatment with formaldehyde under Mannich conditions afforded the corresponding imidazo derivatives. Reaction of Ghloroacetylamino with potassium thiocyanate yielded ethylpyrimidothieno coumarin sulfanylacetate which was used as a versatile precursor for synthesis of other heterocycles. On the other hand, reaction of chloro coumarin carbo nitrile with hydrazine gave the aminopyrazolocoumaine which reacted with bifunctionally compounds to give the substituted pyrimido derivatives. Diazotization and coupling of aminopyrazole with ethylcyanoacetate yielded ethylaminotriazinopyrazolocoumarine carboxylate. Several of the compounds obtained demonstrated considerable antifungal and antibacterial activity in the in vitro test systems.

Synthesis of thiophenes and pyranone fused thiophenes by base induced inter and intramolecular C–S and C–C bond formation: a non-catalytic approach

An efficient and concise one pot synthesis of highly functionalized thiophenes and pyranone fused thiophenes has been delineated through base induced ring transformation of suitably functionalized 2H-pyran-2-ones by ethyl thioglycolate by inter and intramolecular C–S and C–C bond formation.

Chemo-enzymatic synthesis of polyhydroxyalkanoate by an improved two-phase reaction system (TPRS)

In our previous paper, we synthesized poly-3-hydroxybutyrate [P(3HB)] by using the water-organic solvent two-phase reaction system (TPRS), in which thiophenyl (R)-3-hydroxybutyrate [(R)-3HBTP] was used as a precursor of 3HBCoA. We have developed an improved TPRS for the chemo-enzymatic synthesis of polyhydroxyalkanoate (PHA). In this method, acetyl thioester of ethyl thioglycolate (AcETG) was used as a precursor of acetylCoA (AcCoA), which was a donor of CoA. The AcCoA was formed by the ester exchange reaction between CoA in the water phase and AcETG in the organic solvent phase. The AcCoA and free 3-hydroxybutyrate (3HB) in the water phase were converted into 3HBCoA and acetate by a CoA transfer reaction of propionylCoA transferase (PCT). The synthesized 3HBCoA was polymerized sequentially by PHA synthase, and P(3HB) was successfully formed. The maximal yield of P(3HB) was 1.2 g/l under the optimal reaction condition; this is comparable to that of in vivo PHA production. Furthermore, the number of enzymes was reduced and enzyme preparation was simplified by the construction of a fusion protein, PCT-PhaC. The chemo-enzymatic synthesis of P(3HB-co-3-hydroxypropionate) and P(3HB-co-3-mercaptopropionate) was also achieved by the improved TPRS using the fusion protein.

Final Amended Report on the Safety Assessment of Ammonium Thioglycolate, Butyl Thioglycolate, Calcium Thioglycolate, Ethanolamine Thioglycolate, Ethyl Thioglycolate, Glyceryl Thioglycolate, Isooctyl Thioglycolate, Isopropyl Thioglycolate, Magnesium Thioglycolate, Methyl Thioglycolate, Potassium Thioglycolate, Sodium Thioglycolate, and Thioglycolic Acid

This safety assessment includes Ammonium and Glyceryl Thioglycolate and Thioglycolic Acid Butyl, Calcium, Ethanolamine, Ethyl, Isooctyl, Isopropyl, Magnesium, Methyl, Potassium, and Sodium Thioglycolate, as used in cosmetics. Thioglycolates penetrate skin and distribute to the kidneys, lungs, small intestine, and spleen; excretion is primarily in urine. Thioglycolates were slightly toxic in rat acute oral toxicity studies. Thioglycolates are minimal to severe ocular irritants. Thioglycolates can be skin irritants in animal and in vitro tests, and can be sensitizers. A no-observable-adverse-effect level for reproductive and developmental toxicity of 100 mg/kg per day was determined using rats. Thioglycolates were not mutagenic, and there was no evidence of carcinogenicity. Thioglycolates were skin irritants in some clinical tests. Clinically significant adverse reactions to these ingredients used in depilatories are not commonly seen, suggesting current products are formulated to be practically nonirritating under conditions of recommended use. Formulators should take steps necessary to assure that current practices are followed.

A Novel Synthesis of Some New Benzoyl‐Substituted Heterocycles from 2‐Benzoyl‐3‐phenylpent‐2‐ene‐1,5‐dinitrile.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A novel synthesis of some new benzoyl‐substituted heterocycles from 2‐benzoyl‐3‐phenylpent‐2‐ene‐1,5‐dinitrile

Abstractmagnified image2‐Benzoyl‐3‐phenylpent‐2‐ene‐1,5‐dinitrile 1 undergoes bromination with N‐bromosuccinimide (NBS) to afford the bromo derivative 2a. This bromo derivative undergoes reactions with sodium hydrogen sulfide, ethyl thioglycollate, hydroxylamine hydrochloride, hydrazines, cyanoacetamide, cyanacetohydrazide and urea derivatives to afford the thiophene 4, 4H‐thiopyran 6, 4H‐1,2‐oxazine 8, 4H‐pyridazines 10a,b, the pyridine 15, pyrrolo[1,2‐b]pyridazine 17 and the N‐substituted‐pyrrole derivatives 19a‐c respectively.

Reactivity of 4,4‐Dichloro‐1,1‐diphenyl‐2‐azabutadiene Towards Alkoxides and Thiolates: Synthesis of Functionalised π‐Conjugated 2‐Azabutadienes and Unexpected 1,4‐Thiazine Formation

AbstractTreatment of 4,4‐dichloro‐1,1‐diphenyl‐2‐azabuta‐1,3‐diene [Cl2C=C(H)‐N=CPh2] (1) with excess sodium isopropylthiolate or sodium thiophenolate in DMF yielded the 2‐azabutadiene derivatives (RS)2C=C(H)–N=CPh2 (2) (2a R = iPr; 2b R = Ph). Nucleophilic attack of the sodium salt of ethyl thioglycolate on 1 afforded as the sole product the six‐membered heterocyclic compound ethyl 2‐ethoxycarbonylmethylthio‐5,5‐diphenyl‐5,6‐dihydro‐4H‐1,4‐thiazine‐6‐carboxylate (5). The reaction is initiated by substitution of the two vinyl‐bound chloro substituents to give {EtO(O=)CCH2S}2C=C(H)–N=CPh2 (2c) as intermediate. A mechanism that accounts for the subsequent cyclisation reaction is proposed. The 2‐azabutadiene derivative (PhO)2C=C(H)–N=CPh2 (7) was obtained by the reaction of 1 with sodium phenolate. The regioselectivity of the incoming nucleophile is roughly correlated with its hardness/softness in accord with Pearson’s HSAB principle. The molecular structures of 2a,b, 5 and 7 were determined by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2006)

Domino Reactions of 1,2-Diimidoyl-1,2-dichloroethanes. Synthesis of 3-Imino-1,2-dithia-3H-cyclopent-4-enes, 3-Amino-2-thioxo-2,5H-pyrrol-5-ones, 2,3-Diamino-4-thioxo-4H-thiopyrans, and 6-Imino-6H-1,3-oxazines

The reaction of mono- and dilithiated ethyl thioglycolate with 1,2-diimidoyl-1,2-dichloroethanes, aza-analogues of oxalyl chloride, afforded (depending on the reaction conditions) 3-imino-1,2-dithia-3H-cyclopent-4-enes, 3-amino-2-thioxo-2,5H-pyrrol-5-ones, and 2,3-diamino-4-thioxo-4H-thiopyrans. The reaction of the dianion of ethyl hippurate with 1,2-diimidoyl-1,2-dichloroethanes afforded 6-imino-6H-1,3-oxazines.