Author: Jessica.F

Are In Silico Approaches Applicable As a First Step for the Prediction of e-Liquid Toxicity in e-Cigarettes? was written by Zarini, Daniele;Sangion, Alessandro;Ferri, Emanuele;Caruso, Enrico;Zucchi, Sara;Orro, Alessandro;Papa, Ester. And the article was included in Chemical Research in Toxicology in 2020.Electric Literature of C6H10O2 This article mentions the following:

Recent studies have raised concerns about e-cigarette liquid inhalation toxicity by reporting the presence of chems. with European Union CLP toxicity classification. In this scenario, the regulatory context is still developing and is not yet up to date with vaping current reality. Due to the paucity of toxicol. studies, robust data regarding which components in tent. In this study we applied computational methods for studied chems. as a useful tool for predicting the acute toxicity of chems. contained in e-liquids The purpose of t the potential health concerns associated with e-liquid ingredients, (b) to prioritize e-liquid ingredients by calculating the e-tox index, and (c) to estimate acute toxicity of e-liquid mixtures QSAR models were generated using QSARINS software to fill the acute toxicity data gap of 264 e-liquid ingredients. As a second step, the potential acute toxicity of e-liquids mixtures was evaluated. Our preliminary data suggest that a computational approa serve as a roadmap to enable regulatory bodies to better regulate e-liquid composition and to contribute to consumer health protection. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Electric Literature of C6H10O2).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is 绾?valerolactone.Electric Literature of C6H10O2

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Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

A Highly Stereoselective Organocatalytic Tandem Aminoxylation/Aza-Michael Reaction for the Synthesis of Tetrahydro-1,2-Oxazines was written by Zhu, Di;Lu, Min;Chua, Pei Juan;Tan, Bin;Wang, Fei;Yang, Xinhao;Zhong, Guofu. And the article was included in Organic Letters in 2008.Formula: C11H20O4 This article mentions the following:

A facile stereoselective synthesis of multifunctionalized tetrahydro-1,2-oxazines (THOs) has been achieved by the organocatalyzed asym. tandem 浼?aminoxylation/aza-Michael reaction for the C-O/C-N bond formations in moderate to good yields with excellent diastereo- (>99:1 dr) and enantioselectivities (92% to >99% ee). E.g., reaction of di-Me 2-(5-oxopentylidene)malonate (I) with nitrosobenzene, catalyzed by L-proline, gave 84% tetrahydro-1,2-oxazine II (98% ee). In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Formula: C11H20O4).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Formula: C11H20O4

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Regioselective functionalization of nonactivated CH bonds. 2. Photochemical functionalization of the myristoyl group in 1,2-alkanediyl and o-phenylene 4-benzoylbenzoate myristates was written by Dors, Bernhard;Luftmann, Heinrich;Schaefer, Hans J.. And the article was included in Chemische Berichte in 1983.Recommanded Product: 3903-40-0 This article mentions the following:

Me(CH₂)₁₂CO₂QO₂CC₆H₄COPh-4 (Q = CH₂CH₂, trans-1,2-cyclohexanediyl, o-phenylene) were prepared and cyclized photochem. to I, which were converted to Me 7- to 13-oxomyristates. This ketofunctionalization of the remote CH₂ groups in myristic acid was more selective than in 4-PhCOC₆H₄CO₂(CH₂)_nMe (n = 11, 15, 16, 17), and the maximum functionalization occurred more toward the middle, rather than the end, of the chain. The solvent polarity had only a small effect on the selectivity. In the experiment, the researchers used many compounds, for example, 12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0Recommanded Product: 3903-40-0).

12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Esters contain a carbonyl center, which gives rise to 120鎺?C閳ユ弲閳ユ彊 and O閳ユ弲閳ユ彊 angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C閳ユ彊閳ユ弲 bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Recommanded Product: 3903-40-0

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Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Metal-Free Cross-Dehydrogenative C-O Coupling of Carbonyl Compounds with N-Hydroxyimides: Unexpected Selective Behavior of Highly Reactive Free Radicals at an Elevated Temperature was written by Krylov, Igor B.;Lopat’eva, Elena R.;Budnikov, Alexander S.;Nikishin, Gennady I.;Terent’ev, Alexander O.. And the article was included in Journal of Organic Chemistry in 2020.Quality Control of Methyl2-methylbutyrate This article mentions the following:

Cross-dehydrogenative C-O coupling of N-hydroxyimides with ketones, esters, and carboxylic acids was achieved employing the di-tert-Bu peroxide as a source of free radicals and a dehydrogenating agent. The proposed method is exptl. simple and demonstrates the outstanding efficiency for the challenging CH substrates, such as unactivated esters and carboxylic acids. It was shown that N-hydroxyphthalimide drastically affects the oxidative properties of t-BuOOt-Bu by intercepting the t-BuO^{閳?/sup> radicals with the formation of phthalimide-N-oxyl radicals, a species responsible for both hydrogen atom abstraction from the CH reagent and the selective formation of the C-O coupling product by selective radical cross-recombination. The practical applicability of the developed method was exemplified by the single-stage synthesis of com. reagent (known as Baran aminating reagent precursor) from isobutyric acid and N-hydroxysuccinimide, whereas in the standard synthetic approach, four stages are necessary. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Quality Control of Methyl2-methylbutyrate).}

Methyl2-methylbutyrate (cas: 868-57-5) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Quality Control of Methyl2-methylbutyrate

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Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Chemistry of natural substances. VII. Furoquinoline derivatives by condensation of ethyl 2-propynyl malonate with aromatic amines was written by Reisch, Johannes. And the article was included in Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft in 1967.Category: esters-buliding-blocks This article mentions the following:

Under the reaction conditions which are stated by Baker, Lappin, and Riegel (1946) for the preparation of 3-substituted 4-hydroxyquinolin-2-one, malonic acid diarylamides and not 4-hydroxyquinolinones were obtained. By variation of the synthesis from prop-2-ynylmallonic ester and PhNH2 or MeOC5H4-NH2 resp. 5′-methylnordictamine and 5′-methylnorpseudodictaamine or 5′-methylnorfagarine (Ia) and 5′-methylnorpseudofagarine (Ib) resp. were prepared (Method A) A mixture of 11 g. di-Et prop-2-ynylmalonate (I) and 4.7 g. PhNH2 in 25 ml. Ph2O were refluxed 1 hr. to give 66% prop-2-ynylmalonic acid (II) dianilide (IIa), m. 217鎺?(EtOH). (Method B). To 3.8 g. freshly distilled PHNH2 in 150 ml. absolute Et2O was dropped 2 g. prop-2-ynylmalonic acid dichloride in 20 ml. Et2O with stirring and ice cooling to obtain 90% IIa. According to method A was prepared 48% of the corresponding di-O-anisidide, m. 147鎺?(EtOH) of II; 54% of the cyclohexylmalonic acid (III) dianilide, m. 303鎺?(EtOH) and from 6.65 g. di-Et cyclohexylmalonate (IV) and 3.1 g. p-MeOC6H4NH2, 3 g. di-p-anisidide derivative, m. 289-90鎺?(EtOH) of III, beside 1 g. p-anisidide Et ester derivative, m. 158-60鎺?(aqueous EtOH) of III. Heating 6 g. di-Et propylmalonate and 6 g. PhNH2 1 hr. at 190-200鎺?gave 50% propylmalonic acid dianilide (V), m. 200鎺?(EtOH). Hydrogenation of IIa in 80% MeOH at 0鎺?and 760 mm. gave V quant. A mixture of 6.65 g. IV and 2.32 g. PhNH2 in 12.5 ml. Ph2O was heated on the descending cooler until 2.5 ml. EtOH was distilled to give 83% 3-cyclohexyl-4-hydroxy-2(1H)-quinolinone (VI), m. 238-4鎺?(EtOH). Analogously prepared were 90% 6-methoxy derivative m. 235-6鎺?(EtOH), of VI, and 3-propyl-4-hydroxy-2(1H)quinolinone, m. 235鎺? A mixture of 22 g. I and 9.3 g. PhNH2 in 50 ml. was heated on the descending cooler until 10 ml. EtOH was distilled to obtain 74% 2-methylfuro[3,2-c]quinolinone (VII), identified by ir spectroscopy. Also obtained was 16% 2-methylfuro[2,3-b]quinolin-4-one (VIII), m. 275鎺?(HCONMe2H2O). Analogously were prepared 74% Ib m. 248-52鎺?(sublimes), and 13.5% Ia, m. 261鎺? In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Category: esters-buliding-blocks).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is 绾?valerolactone.Category: esters-buliding-blocks

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Stereospecific synthesis of chiral tertiary alkyl aryl ethers via Mitsunobu reaction with complete inversion of configuration was written by Shi, Yao-Jun;Hughes, David L.;McNamara, James M.. And the article was included in Tetrahedron Letters in 2003.Recommanded Product: 19444-23-6 This article mentions the following:

Mitsunobu reaction of (S)-EtCMe(OH)COOMe with 4-(benzyloxy)phenol provides (R)-4-PhCH₂OC₆H₄OCMeEtCOOMe in moderate yield at elevated temperatures (80-100鎺?. The S_N2 displacement pathway is evident by complete inversion of the (S)-alc. to the (R)-ether. Several analogous reactions were also performed. In the experiment, the researchers used many compounds, for example, Benzyl 2-hydroxy-2-methylpropanoate (cas: 19444-23-6Recommanded Product: 19444-23-6).

Benzyl 2-hydroxy-2-methylpropanoate (cas: 19444-23-6) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Recommanded Product: 19444-23-6

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Ester – Wikipedia,
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Regiospecific Synthesis of Bicyclo- and Heterobicyclo-gem-difluorocyclobutenes Using Functionalized Fluoroallenes and a Novel Mo-Catalyzed Intramolecular [2 + 2] Cycloaddition Reaction was written by Shen, Qilong;Hammond, Gerald B.. And the article was included in Journal of the American Chemical Society in 2002.Computed Properties of C10H14O4 This article mentions the following:

The synthesis of functionalized gem-difluoroallenes served as a platform for an unprecedented molybdenum-catalyzed intramol. allene-alkyne [2+2]-cycloaddition that produced difluorobicyclooctadienes, a hitherto unknown class of bicyclo- and heterobicyclo-CF₂-containing cyclobutenes. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Computed Properties of C10H14O4).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Computed Properties of C10H14O4

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Dynamic combinatorial chemistry to identify binders of ThiT, an S-component of the energy-coupling factor transporter for thiamin was written by Monjas, Leticia;Swier, Lotteke J. Y. M.;Setyawati, Inda;Slotboom, Dirk J.;Hirsch, Anna K. H.. And the article was included in ChemMedChem in 2017.Reference of 19432-68-9 This article mentions the following:

We applied dynamic combinatorial chem. (DCC) to identify ligands of ThiT, the S-component of the energy-coupling factor (ECF) transporter for thiamin in Lactococcus lactis. We used a pre-equilibrated dynamic combinatorial library (DCL) and saturation-transfer difference (STD) NMR spectroscopy to identify ligands of ThiT. This is the 1st report in which DCC has been used for fragment growing to an ill-defined pocket, and one of the 1st reports for its application with an integral membrane protein as target. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Reference of 19432-68-9).

Methyl 2-thienylacetate (cas: 19432-68-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Reference of 19432-68-9

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Effects of modified atmosphere and sugar immersion on physiology and quality of fresh-cut ‘Braeburn’ apples was written by Rux, G.;Bohne, K.;Huyskens-Keil, S.;Ulrichs, Ch.;Hassenberg, K.;Herppich, W. B.. And the article was included in Food Packaging and Shelf Life in 2021.Safety of Methyl2-methylbutyrate This article mentions the following:

Fresh-cut fruits are highly perishable and show a short shelf life. Therefore, storage in sugar syrup is com. used to delay undesirable metabolic changes and to prevent browning. Investigations on the effects of syrup application on volatile organic compounds (VOCs), important for the consumers’ acceptance, are rare. It is, however, known that low O₂ availability, as found in fruit slices after immersion, may result in the formation of unwanted off-odor. This neg. affects the sensory quality of fresh-cuts. In the present study, fresh-cut ‘Braeburn’ apples were comparatively stored in air, in three modified atmospheres (O₂: 10, 5 and approx. 0%; CO₂: 10, 15 and 20%) or in sugar syrup (20% sugar content). Relevant quality, physiol. and microbiol. parameters were evaluated on days 3, 6 and 10 of storage. Particular focus was laid on the evaluation of VOC emission to indicate biosynthetic responses that affect aroma-relevant VOCs. Atm. storage of apple slices, among others, increased the emission of Et acetate, which may create off-odor and neg. affects the customers’ acceptance. In contrast, syrup-immersion of apple slices resulted in a pronounced loss of aroma but prevented the occurrence of off-odor. The results indicated metabolic changes, which were independent of O₂ availability. High CO₂ or VOCs concentrations in the fruit tissue may inhibit esterification or may induce a feedback inhibition of VOC synthesis. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Safety of Methyl2-methylbutyrate).

Methyl2-methylbutyrate (cas: 868-57-5) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Safety of Methyl2-methylbutyrate

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Ester – Wikipedia,
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Catalytic synthesis of 2,2′-arylmethylenebis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-ones) and 3,3,6,6-tetramethyl-9-aryl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-diones was written by Dikusar, E. A.;Potkin, V. I.;Kozlov, N. G.;Pavlyuchenkova, A. S.;Murashova, M. Yu.;Petkevich, S. K.;Kletskov, A. V.;Polikarpov, A. P.;Ogorodnikova, M. M.;Zolotar’, R. M.;Chepik, O. P.. And the article was included in Russian Journal of Organic Chemistry in 2013.Name: 4-Formyl-2-methoxyphenyl isobutyrate This article mentions the following:

Hexahydroxanthenediones I [R = Ph, 4-HOC₆H₄, 4-MeOC₆H₄, 4-HO₂CC₆H₄, 2,4-(HO)₂C₆H₃, 2-HO-3-MeOC₆H₃, 3-HO-4-MeOC₆H₃, 1,3-benzodioxol-5-yl, 3-MeO-4-HOC₆H₃, 2-Br-4,5-(MeO)₂C₆H₂, 3-MeO-4-R¹COOC₆H₃, 3-EtO-4-HOC₆H₃, 3-EtO-4-R¹COOC₆H₃, 3-MeO-4-R²COOC₆H₃, 3-EtO-4-R²COOC₆H₃, 3-MeO-4-R³COOC₆H₃, 3-EtO-4-R³COOC₆H₃, 3-MeO-4-R⁴COOC₆H₃, 3-EtO-4-R⁴COOC₆H₃; R¹ = Me(CH₂)_n, Me₂CH, Me₂CHCH₂, Me₃CH, Me₂CHCH₂CH₂, Ph; R² = 5-phenyl-3-isoxazolyl; R³ = 5-(4-methylphenyl)-3-isoxazolyl; R⁴ = 4,5-dichloro-3-isothiazolyl; n = 0-4, 8, 11, 16] were prepared in two steps from aryl aldehydes RCHO and dimedone (5,5-dimethyl-1,3-cyclohexanedione) or from acid chlorides R³COCl or R⁴COCl and I [R = 3-MeO-4-HOC₆H₄, 3-EtO-4-HOC₆H₄]. Condensation of benzaldehydes RCHO [R = Ph, 4-HOC₆H₄, 4-MeOC₆H₄, 4-HO₂CC₆H₄, 2,4-(HO)₂C₆H₃, 2-HO-3-MeOC₆H₃, 3-HO-4-MeOC₆H₃, 1,3-benzodioxol-5-yl, 3-MeO-4-HOC₆H₃, 2-Br-4,5-(MeO)₂C₆H₂, 3-MeO-4-R¹COOC₆H₃, 3-EtO-4-HOC₆H₃, 3-EtO-4-R¹COOC₆H₃, 3-MeO-4-R²COOC₆H₃, 3-EtO-4-R²COOC₆H₃, 3-MeO-4-R³COOC₆H₃, 3-EtO-4-R³COOC₆H₃, 3-MeO-4-R⁴COOC₆H₃, 3-EtO-4-R⁴COOC₆H₃; R¹ = Me(CH₂)_n, Me₂CH, Me₂CHCH₂, Me₃CH, Me₂CHCH₂CH₂, Ph; R² = 5-phenyl-3-isoxazolyl; n = 0-4, 8, 11, 16] with dimedone gave arylmethylenebis(dimethylhydroxycyclohexenones) (or in some cases provided I directly). Cyclocondensation of the intermediate arylmethylenebis(dimethylhydroxycyclohexenones) in the presence of the sulfo cation exchanger FIBAN K-1 gave hexahydroxanthenediones. In some cases, the arylisoxazolylcarboxylic and dichloroisothiazolylcarboxylic esters underwent partial or full hydrolysis during the (attempted) preparation of the corresponding hexahydroxanthenediones. In the experiment, the researchers used many compounds, for example, 4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4Name: 4-Formyl-2-methoxyphenyl isobutyrate).

4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Name: 4-Formyl-2-methoxyphenyl isobutyrate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics