Tag: 100-200

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^{鈥?/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

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

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 纬-valerolactone.Electric Literature of C6H10O2

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

Microbial diversity and chemical characteristics of Coffea canephora grown in different environments and processed by dry method was written by Pereira, Priscila Vargas;Bravim, Danielle Goncalves;Grillo, Renata Pancini;Bertoli, Larissa Diirr;Osorio, Vanessa Moreira;da Silva Oliveira, Daniela;da Cruz Pedrozo Miguel, Maria Gabriela;Schwan, Rosane Freitas;de Assis Silva, Samuel;Coelho, Jussara Moreira;Bernardes, Patricia Campos. And the article was included in World Journal of Microbiology & Biotechnology in 2021.Quality Control of Ethyl 2-hydroxybenzoate This article mentions the following:

This study aimed to assess the microbial diversity in Coffea canephora grown in four different environments of Espirito Santo state, Brazil. Coffee cherries of two different altitudes (300 and 600 m) and two terrain aspects (Southeast-facing and Northwest-facing slopes) were processed by the dry method. Samples were collected during the drying/fermentation process. Microorganisms were counted, isolated, and identified by MALDI-TOF, followed by sequencing of the ribosomal region. Sugars and organic acids were quantified by HPLC and volatile compounds of the roasted coffees were evaluated by GC-MS. Bacteria population presented a significant number of isolates as well as higher counts during the drying/fermentation process with respect to the population of yeasts. The principal genera of microorganisms found were Bacillus, Pichia, Candida, and Meyerozyma. Meyerozyma guilliermondii was the most frequent yeast in all environments. On the other hand, Pichia kluyveri was found only in coffee cherries from the 600 m altitude. The highest concentration of acetic and succinic acids observed was 6.06 mg/g and 0.84 mg/g, resp. Sucrose concentrations ranged from 0.68 to 5.30 mg/g, fructose from 1.30 to 4.60 mg/g, and glucose from 0.24 to 1.25 mg/g. Thirty-six volatile compounds, belonging to the groups of pyrazines, alcs., aldehydes, ketones, and furans were identified in roasted coffee, with differences between altitude and terrain aspects. Information about microbial diversity is crucial to better understand the coffee quality and distinct characteristics of coffee produced in different environments. Graphic abstract: [graphic not available: see fulltext] In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Quality Control of Ethyl 2-hydroxybenzoate).

Ethyl 2-hydroxybenzoate (cas: 118-61-6) 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. 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.Quality Control of Ethyl 2-hydroxybenzoate

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

Evolution Analysis of Free Fatty Acids and Aroma-Active Compounds during Tallow Oxidation was written by Song, Shiqing;Zheng, Feiting;Tian, Xiaoyan;Feng, Tao;Yao, Lingyun;Sun, Min;Shi, Lei. And the article was included in Molecules in 2022.Application In Synthesis of 5-Ethyldihydrofuran-2(3H)-one This article mentions the following:

To explore the role of fatty acids as flavor precursors in the flavor of oxidized tallow, the volatile flavor compounds and free fatty acid (FFAs) in the four oxidization stages of tallow were analyzed via gas chromatog. (GC)-mass spectrometry (MS), the aroma characteristics of them were analyzed by GC-olfactory (GC-O) method combined with sensory anal. and partial least-squares regression (PLSR) anal. 12 common FFAs and 35 key aroma-active compounds were obtained. Combined with the results of odor activity value (OAV) and FD factor, benzaldehyde was found to be an important component in unoxidized tallow. (E,E)-2,4-Heptadienal, (E,E)-2,4-decadienal, (E)-2-nonenal, octanal, hexanoic acid, hexanal and (E)-2-heptenal were the key compounds involved in the tallow flavor oxidation The changes in FFAs and volatile flavor compounds during oxidation and the metabolic evolution of key aroma-active compounds are systematically summarized in this study. The paper also provides considerable guidance in oxidation control and meat flavor product development. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Application In Synthesis of 5-Ethyldihydrofuran-2(3H)-one).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is 纬-valerolactone.Application In Synthesis of 5-Ethyldihydrofuran-2(3H)-one

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

2-Pyrrolidinylideneureas, a new class of central nervous system agents was written by Rasmussen, C. R.;Gardocki, Joseph F.;Plampin, James N.;Twardzik, Barbara L.;Reynolds, Brian E.;Molinari, Albert J.;Schwartz, Norman;Bennetts, Walter W.;Price, Beth E.;Marakowski, Janis. And the article was included in Journal of Medicinal Chemistry in 1978.Quality Control of 3-Cyanophenylisocyanate This article mentions the following:

Pyrrolidinylideneureas (I) were prepared and screened for pharmacol. activity. I (X = H, 4-NO₂, 3-Br, 3-F, 3-Cl, 3-Me) had anxiolytic activity. I 2,6-disubstituted with Me, Cl, and Br imparted potent muscle-relaxant properties which appear to be centrally mediated. A significant separation of the anxiolytic and muscle-relaxant properties fromother CNS activities, eg, anticonvulsant, sedative, and hypnotic, was achieved. I were prepared by treating 2-imino-1-methylpyrrolidines with aryl isocyanates. In the experiment, the researchers used many compounds, for example, 3-Cyanophenylisocyanate (cas: 16413-26-6Quality Control of 3-Cyanophenylisocyanate).

3-Cyanophenylisocyanate (cas: 16413-26-6) 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 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.Quality Control of 3-Cyanophenylisocyanate

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

Autoxidation in the presence of alcohols and protons. III. Autoxidation of cyclenes, hydroarenes, and hydroheterocycles was written by Treibs, Wilhelm;Schoellner, Roll. And the article was included in Chemische Berichte in 1961.Computed Properties of C11H14O3 This article mentions the following:

Cyclohexene (I) and Tetralin (II) yield by autoxidation in the presence of alcs. and protons 伪-ketones and also under cleavage of the C-C bond neighboring the place of the O attack (CH₂CH₂-CHO)₂ (III) and o-HOC₆H₄(CH₂)₃CHO (IV) which are stabilized as the acetals. The autoxidation of I yielded also as the result of a Prilesehayev-type reaction o-methoxycyclohexanol (V), 2-methoxy-1,3-cyclohexanediol (VI), and 3-methoxycyclohexene (VII). 1,2,3,4,10,11-Hexahydrodiphenylene oxide (VIII) yields similarly 1,2,3,4,11,12hexahydro-12-methoxydibenzodioxane (IX) and 1,2,3,4,10,11-hexahydro-10-methoxydiphenylene oxide (X). I (200 g.), 1500 cc. absolute MeOH, and 3 cc. concentrated H₂SO₄ irradiated 120 hrs. under O at 60掳 with ultraviolet light, neutralized with NaHCO₃, decanted, and fractionated gave 7-8 g. VII, b. 135-6掳, n¹_D² 1.463, 14 g. distillate, b₁₆ 67-9掳 n¹_D⁰ 1.4700, which chromatographed yielded cyclohexen-3-one, n²_D⁰ 1.4798 (2,4-dinitrophenylhydrazone, m. 164-6掳), and V, n¹_D⁰ 1.4612, 3-4 g. cyclic di-Me acetal of III, b₁₅ 82-4掳, n²_D⁰ 1.432 [bis(2,4-dinitrophenylhydrazone) of III, m. 216-17掳], and 29 g. distillate, b₁₅ 98-118掳, which chromatographed gave 50-5% bis(dimethyl acetal) of III, b₁₂ 103-8掳 26-30% MeO₂C(CH₄)₄CH(OMe)₂ (2,4-dinitrophenylhydra zone m. 101掳), and 18-20% VI, n²_D⁰ 1.468. II (200 g.), 1500 cc. absolute MeOH, and 2.5 cc. concentrated H₂SO₄ irradiated 240 hrs. under O at 60掳, and the crude product (30 g.) distilled gave 11 g. 伪-tetralone, b₁₂ 130掳 (2,4-dinitrophenylhydrazone m. 257-8掳), 10 g. di-Me acetal of IV (2,4-dinitrophenylhydrazone of IV m. 148掳), and 15-20% o-HOC₆H₄(CH₂)₃CO₂Me. Diphenylene oxide in absolute EtOH hydrogenated at 120掳/110 atm. gave 45-50% VIII, b_0.04 51-2掳, n²_D⁰ 1.545, and some perhydrodiphenylene oxide, b₂₀ 130-4掳, and 0-phenylcyclohexanol, b₂0 149-53掳. VIII (150 g.) in 1500 cc. absolute MeOH and 2.5 cc. concn H₂SO₄ autoxidized under O during 96 hrs. at 60掳, neutralized with NH₃, concentrated, and distilled gave a crude product, b_0.3 93-6掳, n²_D⁰ 1.541, which chromatographed on Al₂O₃ yielded X, n²_D⁰ 1.5533, and IX. X (1 g.), 10 cc. 2N HCl, and 5 cc. MeOH refluxed 6 hrs., neutralized with NH₃, concentrated, and chromatographed gave the 10-OH analog of X, m. 102掳. IX (1 g.), 20 cc. 0.1N HCl, and 5 cc. MeOH refluxed 6 hrs., and the crude product chromatographed on Al₂O₂ yielded 0.6 g. pure IX, m. 64-8掳, n⁸_D⁰ 1.542, and an unidentified material. Cumene (150 g.) autoxidized under the usual conditions during 360 hrs. gave 10-12 g. product containing 12-15% AcPh (2,4-dinitrophenylhydrazone m. 247掳). Com. cumene hydroperoxide (60%) (20 g.) added dropwise to 0.5 cc. concentrated H₂SO₄ in 250 cc. absolute MeOH, cooled, neutralized with NaHCO₃, and fractionated yielded 6.7 g. cumene and 1.4 g. AcPh. In the experiment, the researchers used many compounds, for example, Methyl 4-(2-hydroxyphenyl)butanoate (cas: 93108-07-7Computed Properties of C11H14O3).

Methyl 4-(2-hydroxyphenyl)butanoate (cas: 93108-07-7) 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. 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.Computed Properties of C11H14O3

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

Cyclization of alk-5-ynyl ketones promoted by Tf₂NH and In(OTf)₃: selective synthesis of 5- and 7-membered carbocycles was written by Kinoshita, Hidenori;Miyama, Chika;Miura, Katsukiyo. And the article was included in Tetrahedron Letters in 2016.Computed Properties of C10H14O4 This article mentions the following:

Combined use of Tf₂NH and In(OTf)₃ effectively promotes the cyclization of alk-5-ynyl ketones to cyclopent-1-enyl ketones at 30 掳C [e.g., I 鈫?II (77%)]. Single use of Tf₂NH or In(OTf)₃ requires heating at 50 掳C for efficient cyclization. The In(OTf)₃-promoted reaction of certain alk-5-ynyl ketones gives cyclohept-2-enones mainly. 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. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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.Computed Properties of C10H14O4

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

Influence of Freezing and Different Drying Methods on Volatile Profiles of Strawberry and Analysis of Volatile Compounds of Strawberry Commercial Jams was written by Abouelenein, Doaa;Mustafa, Ahmed M.;Angeloni, Simone;Borsetta, Germana;Vittori, Sauro;Maggi, Filippo;Sagratini, Gianni;Caprioli, Giovanni. And the article was included in Molecules in 2021.Recommanded Product: 868-57-5 This article mentions the following:

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and flavor. Drying fruits to produce a powder represents one of the possible conservation methods to extend their shelf-life. The aim of the present study was to compare the influence of freezing and different drying methods on the volatile profile of strawberry using the HS-SPME/GC-MS method, in addition to anal. of strawberry jam volatiles. A total of 165 compounds were identified, accounting for 85.03-96.88% of the total volatile compositions Results and PCA showed that freezing and each drying process affected the volatile profile in a different way, and the most remarkable representative differential volatiles were Et hexanoate, hexyl acetate, (E)-2-hexenyl acetate, mesifurane, (E)-nerolidol, 纬-decalactone, 1-hexanol, and acetoin. Shade air-dried, frozen, freeze-dried, and oven-dried 45掳C samples retained more of the fruity and sweet aromas of strawberry, representing more than 68% of the total aroma intensity according to the literature. In contrast, the microwave-drying method showed drastic loss of fruity esters. Strawberry jams demonstrated complete destruction of esters and alcs. in most jams, while terpenes were significantly increased. These findings help better understand the aroma of strawberry and provide a guide for the effects of drying, freezing, and jam processing. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Recommanded Product: 868-57-5).

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. 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: 868-57-5

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

Deeper Insight into the Volatile Profile of Rosa willmottiae with Headspace Solid-Phase Microextraction and GC-MS Analysis was written by Jiao, Ruifang;Gao, Ping;Gao, Xinfen. And the article was included in Molecules in 2022.Reference of 105-87-3 This article mentions the following:

As the distribution center of Rosa in the world, China has abundant wild germplasm resources, which can contribute to the breeding of modern roses. To explore the potential value of wild roses distributed in the Sichuan-Tibet region, solid phase microextraction (SPME) and gas chromatog.-mass spectrometry (GC-MS) were used to determine the volatile organic compounds (VOCs) in Rosa willmottiae flowers at three flowering stages (bud stage, initial flowering stage, full flowering stage). Meanwhile, we compared the VOCs of R. willmottiae with different phenotypes (double flowers and single flowers). A total of 74 volatile compounds were identified. The results show that the essential substances belong to alcs. and terpenoids. The main volatile organic compounds are 2-Ph ethanol (20.49%), benzyl alc. (10.69%), 尾-maaliene (8.66%), geranyl acetate (8.47%), and (+)-伪-long pinene (6.127%). Different flowering stages had great influence on the volatile profile, from the bud stage to full flowering stage; the content of terpenoids released decreased by 6.17%, whereas alcs. and esters increased by 8.58% and 11.56%, resp. The chem. diversity and the content of the main components with a different phenotype were not significantly different. Our result will provide a theor. basis for the development and utilization of Rosa willmottiae in Sichuan and Tibet. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Reference of 105-87-3).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) 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. 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 105-87-3

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

A metabolomics comparison of Lactobacillus communities isolated from breast milk and camel milk and Lactobacillus apis isolated from bee gut during cereals-based fermentation vs. Lactobacillus plantarum as a reference was written by Ghamry, Mohamed;Li, Li;Zhao, Wei. And the article was included in LWT–Food Science and Technology in 2021.HPLC of Formula: 706-14-9 This article mentions the following:

New and unconventional sources of probiotics may provide unique health efficacy by producing healthy, bioactive compounds The current study evaluates the fermentation efficiency and intrinsic effects on the bioactive substances produced by Lactobacillus apis (L. apis) as a novel strain isolated from the bumblebee gut, two different isolated Lactobacillus communities from breast milk (L.BM) and camel milk (L.CM). Lactobacillus plantarum (L. plantarum) was used as a reference during rice and oats fermentation The obtained results indicated that L.BM and L. CM treatments gave the highest production of phenolics and flavonoids values for different substrates and had the highest impact on the antioxidant capacity. All treatments demonstrated the ability to improve protein quality and properties significantly as compared to non-fermented flours. The best patterns were obtained with L.BM, followed by L. apis and L.CM compared with L. plantarum and non-fermented rice samples. The L.BM and L. apis showed a significant enhancement of volatile components in fermented rice, while L. CM displayed a pronounced effect on volatile production among oats treatments. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9HPLC of Formula: 706-14-9).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) 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. 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.HPLC of Formula: 706-14-9

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