Month: February 2023

Pyrrole studies. VI. The N-H stretching frequencies of substituted pyrroles: methyl and carbethoxy substituents was written by Jones, R. Alan;Moritz, A. G.. And the article was included in Spectrochimica Acta in 1965.Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate This article mentions the following:

The ir spectra of some substituted pyrroles were examined in the N-H stretching region under high resolution in CCl₄. In all cases 2 concentration-independent bands were observed. For compounds with a carbethoxy group in the α position, this is attributed to rotational isomerism. In other cases the 2nd band arises from interaction with the out-of-plane deformation vibration of the N-H group, producing a hot band. An analysis of the data for pyrroles containing Me and carbethoxy substituents, shows that the effect of each group on the N-H stretching frequency is independent of other substituents and is additive. The frequencies can be represented by a single equation, ν_NH = 3496 – 9n_αCH₃ + 2n_βCH₃ – 13n_βCO₂Et – {¹⁴₃₁n_αCO₂Et, where n_α and n_β are the number of substituents in the α and β positions, resp. In the last term, the coefficient is 14 or 31. In the experiment, the researchers used many compounds, for example, Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate).

Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7) 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. 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.Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate

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

Honeycomb-like 2D metal-organic polyhedral framework exhibiting selectively adsorption of CO₂ was written by Du, Liting;Miao, Yinchun;Zheng, Baishu;Ma, Mengtao;Zhang, Jinchi. And the article was included in Journal of Solid State Chemistry in 2021.Recommanded Product: 313648-56-5 This article mentions the following:

A new honeycomb-like 2D Metal-organic polyhedral framework, {Cu_3.75(BrCPEIP)_2.5璺?H₂O)_2.75璺疍MF}_n (NJFU-5, H₃BrCPEIP = 5-((3-bromo-5-carboxyphenyl)ethynyl)isophthalic acid) was solvothermally synthesized and structurally characterized, which shows a BET surface area of 473 m² g^-1. Meanwhile, NJFU exhibits a comparably higher CO₂ adsorption capacity of 37.0 cm³ g^-1 (4.6 wt%) at 1 bar and 298 K in 2D MOF family, and a high CO₂ selective adsorption toward N₂ and CH₄ as well. In the experiment, the researchers used many compounds, for example, Dimethyl 5-ethynylisophthalate (cas: 313648-56-5Recommanded Product: 313648-56-5).

Dimethyl 5-ethynylisophthalate (cas: 313648-56-5) 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.Recommanded Product: 313648-56-5

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

Analysis of characteristic volatile flavor components of preserved Lao-Xiang-Huang of Chaozhou was written by Lin, Liang-jing;Cai, Hui-tian;Bao, Han;Huang, Xue-ying;Chen, Xi;Gao, Xiang-yang. And the article was included in Xiandai Shipin Keji in 2021.Synthetic Route of C6H12O2 This article mentions the following:

In this study, the volatile flavor components of different brands of preserved Lao-Xiang-Huang from the Chaoshan area were analyzed based on gas chromatog.-ion mobility spectrometry GC-IMS. A total of 9 types and 70 species were detected, including 8 esters (6%閳?2%), 14 aldehydes (10%閳?4%), 12 alcs. (13%閳?7%), 3 ketones (3%閳?%), 23 terpenoids (49%閳?2%), 6 acids (1%閳?%), 3 furans (2%閳?%), 1 thiazole (0.4%閳?.5%) and 1 pyrazine (0.6%閳?.6%). Through the calculation and anal. of relative activity value (ROAV), the key volatile flavor contributors of (ROAV>1) were obtained, including geraniol, citronellol, linalool, 1,8-cineole-M, 1,8-cineole-D, myrcene-M, methional, 3-methylbutanal, 3-methylbutanol, propanal, Me 2-methylbutanoate, 1-phenylethanol and nonanal. Among them, methional contributed the most to the flavor of the preserved Lao-Xiang-Huang. Principal component anal. (PCA) can effectively distinguish the samples of different brands. Partial least squares discriminant anal. (PLS-DA) combined with one-way ANOVA was used to screen 15 marker volatile compounds (VIP>1). GC-IMS can distinguish different brands of preserved Lao-Xiang-Huang, and allow rapid anal. of the differences in volatile compounds, thereby providing a reference for qual. and quant. research on the characteristic flavor components of preserved Lao-Xiang-Huang. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Synthetic Route of C6H12O2).

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. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Synthetic Route of C6H12O2

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

Effect of microwave and hot air treatment on enzyme activity, oil fraction quality and antioxidant activity of wheat germ was written by Meriles, Silvina Patricia;Penci, Maria Cecilia;Curet, Sebastien;Boillereaux, Lionel;Ribotta, Pablo Daniel. And the article was included in Food Chemistry in 2022.Recommanded Product: 5-Ethyldihydrofuran-2(3H)-one This article mentions the following:

The aim of this work was to study the effects of microwaves (MW) and hot air (HA) treatments on enzyme activities and quality parameters in wheat germ (WG). Both MW and HA were effective at inactivating lipases. MW treatment inactivated lipases more at lower temperatures (60 and 70鎺矯) than HA (150-200鎺矯). Peroxide values, acidity, and fatty acid profiles of WG oil remained unaltered after HA and MW treatments. Loss of 浼?tocopherol contents was observed following HA treatment, but total tocopherol content remained above 77% baselines values in all treated samples. The main antioxidant mechanism of WG extracts was associated with inactivation of radicals, rather than reducing capacity. MW treatment at 60 and 70鎺矯 enhanced radical scavenging activity, while total polyphenol contents and reducing capacities were neg. affected. Therefore, MW treatment is a promising technol. to stabilize WG, retaining quality and antioxidant activity. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Recommanded Product: 5-Ethyldihydrofuran-2(3H)-one).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) 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.Recommanded Product: 5-Ethyldihydrofuran-2(3H)-one

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

Absolute configuration of in situ crystallized (+)-绾?decalactone was written by Patzer, Michael;Noethling, Nils;Goddard, Richard;Lehmann, Christian W.. And the article was included in Chemistry (Basel, Switzerland) in 2021.Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one This article mentions the following:

Knowledge about the absolute configuration of small bioactive organic mols. is essential in pharmaceutical research because enantiomers can exhibit considerably different effects on living organisms. X-ray crystallog. enables chemists to determine the absolute configuration of an enantiopure compound due to anomalous dispersion. Here, we present the determination of the absolute configuration of the flavoring agent (+)-绾?decalactone, which is liquid under ambient conditions. Single crystals were grown from the liquid in a glass capillary by in situ cryo-crystallization Diffraction data collection was performed using Cu-K浼?radiation. The absolute configuration was confirmed. The mol. consists of a linear aliphatic non-polar backbone and a polar lactone head. In the solid state, layers of polar and non-polar sections of the mol. alternating along the c-axis of the unit cell are observed In favorable cases, this method of absolute configuration determination of pure liquid (bioactive) agents or liquid products from asym. catalysis is a convenient alternative to conventional methods of absolute structure determination, such as ORD, vibrational CD, UV-visible spectroscopy, use of chiral shift reagents in proton NMR and Coulomb explosion imaging. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) 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.Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one

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

Design of Non-nucleoside Inhibitors of HIV-1 Reverse Transcriptase with Improved Drug Resistance Properties. 2. was written by Freeman, George A.;Andrews, C. Webster III;Hopkins, Andrew L.;Lowell, Gina S.;Schaller, Lee T.;Cowan, Jill R.;Gonzales, Stephen S.;Koszalka, George W.;Hazen, Richard J.;Boone, Lawrence R.;Ferris, Rob G.;Creech, Katrina L.;Roberts, Grace B.;Short, Steven A.;Weaver, Kurt;Reynolds, David J.;Milton, John;Ren, Jingshan;Stuart, David I.;Stammers, David K.;Chan, Joseph H.. And the article was included in Journal of Medicinal Chemistry in 2004.Synthetic Route of C11H20O4 This article mentions the following:

HIV-1 nonnucleoside reverse transcriptase inhibitors (NNRTIs) are part of the combination therapy currently used to treat HIV infection. The features of a new NNRTI drug for HIV treatment must include selective potent activity against both wild-type virus as well as against mutant virus that have been selected by use of current antiretroviral treatment regimens. Based on analogy with known HIV-1 NNRTI inhibitors and modeling studies utilizing the x-ray crystal structure of inhibitors bound in the HIV-1 RT, a series of substituted 2-quinolones was synthesized and evaluated as HIV-1 inhibitors. In the experiment, the researchers used many compounds, for example, Diethyl isobutylmalonate (cas: 10203-58-4Synthetic Route of C11H20O4).

Diethyl isobutylmalonate (cas: 10203-58-4) 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. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Synthetic Route of C11H20O4

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

Self-assembled sulfated zirconia nanocrystals with mesoscopic void space synthesized via ionic liquid as a porogen and its catalytic activity for the synthesis of biodiesels was written by Banerjee, Biplab;Bhunia, Subhajit;Bhaumik, Asim. And the article was included in Applied Catalysis, A: General in 2015.HPLC of Formula: 106-79-6 This article mentions the following:

Self-assembled ZrO₂ nanocrystals have been synthesized through a facile chem. route via steam-assisted ionothermal method using 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) as a porogen. The template-free material has been sulfonated by 1(N) H₂SO₄ at room temperature followed by calcination in air at 723 K. Both ZrO₂ and the sulfated zirconia are thoroughly characterized by powder X-ray diffraction (PXRD), ultra high-resolution transmission electron microscopy (UHR-TEM), Fourier transform IR spectroscopy (FT-IR), FE-SEM, N₂ sorption, and NH₃-TPD analyses. The sulfated material has been employed as efficient and environmentally benign heterogeneous catalyst for the synthesis of biodiesels based on long chain fatty acid esters. The catalyst can be easily recovered and reused at least for five times without significant decrease in its catalytic activity. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6HPLC of Formula: 106-79-6).

Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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: 106-79-6

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

Selective electrolytic fluorinations in 70% HF/30% pyridine was written by Lee, Sarah M.;Roseman, Jamie M.;Zartman, C. Blair;Morrison, Eamonn P.;Harrison, Sean J.;Stankiewicz, Corrie A.;Middleton, W. J.. And the article was included in Journal of Fluorine Chemistry in 1996.Recommanded Product: Ethyl 2-(4-fluorophenyl)acetate This article mentions the following:

The selective fluorination of compounds containing benzylic hydrogen atoms was accomplished by electrolysis in a mixture of 70% HF and 30% pyridine (Olah’s reagent) using a square wave a.c. (1.76-2.75 V, 0.02-0.05 Hz) and Pt electrodes. This method can be used in the laboratory to prepare conveniently gram-size quantities of monofluorinated products. An ion radical mechanism is proposed. In the experiment, the researchers used many compounds, for example, Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2Recommanded Product: Ethyl 2-(4-fluorophenyl)acetate).

Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2) 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. 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.Recommanded Product: Ethyl 2-(4-fluorophenyl)acetate

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

Plastic additives in ambient fine particulate matter in the Pearl River Delta, China: High-throughput characterization and health implications was written by Liu, Xiaotu;Zeng, Xiaowen;Dong, Guanghui;Venier, Marta;Xie, Qitong;Yang, Mo;Wu, Qizhen;Zhao, Fanrong;Chen, Da. And the article was included in Environmental Science & Technology in 2021.Computed Properties of C20H26O4 This article mentions the following:

Elucidation of the chem. components of airborne fine particulate matter (PM_2.5) facilitates the characterization of atm. contamination sources and associated human exposure risks. In the present study, we employed a high-throughput anal. approach to investigate the abundance and distribution of 163 plastic additives in ambient PM_2.5 collected from 94 different sites across the Pearl River Delta region, China. These chems. are from six categories, including organophosphate esters (OPEs), phthalate esters (PAEs), PAE replacements, bisphenol analogs, UV stabilizers, and antioxidants. Ninety-three of them exhibited a detection frequency greater than 50% in PM_2.5, while the combined concentrations of target plastic additives ranged from 610 to 49,400娓璯/g (median: 3500娓璯/g) across sites. By category, concentrations of PAEs (median: 2710娓璯/g) were one to three orders of magnitude greater than those of other groups, followed by PAE replacements (540娓璯/g) and OPEs (76.2娓璯/g). Chem.-dependent exposure risks to PM_2.5-bound plastic additives were characterized via the estimated daily intake and hazard quotient (HQ) approaches, which resulted in two different risk prioritization systems. Although the HQ approach suggested no or very low health concerns when considering individual chems., the complexity of co-concurrent chems. in PM_2.5 raises the concern on potential health risks from exposure to airborne particles and a cocktail of chem. components. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Computed Properties of C20H26O4).

Dicyclohexyl phthalate (cas: 84-61-7) 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 C20H26O4

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

One-pot synthesis of 5-alkylthio-3H-1,2-dithiole-3-thiones was written by Aimar, Mario L.;Rossi, Rita H.. And the article was included in Tetrahedron Letters in 1996.Application In Synthesis of malonic acid dibutyl ester This article mentions the following:

Dialkyl malonate esters RO₂CCHR¹CO₂R (R = Et, n-Bu, n-octyl, R¹ = H; R = Et, R¹ = PhCH₂) reacted with P₂S₅/S₈ in boiling xylene and with 2-mercaptobenzothiazole/ZnO as catalyst to yield 5-alkylthio-3H-1,2-dithiole-3-thiones I as major products. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Application In Synthesis of malonic acid dibutyl ester).

malonic acid dibutyl ester (cas: 1190-39-2) 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. 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. Application In Synthesis of malonic acid dibutyl ester

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