Month: February 2023

Enantiomeric Separation on a Homochiral Porous Organic Cage-Based Chiral Stationary Phase by Gas Chromatography was written by Li, Hong-Xing;Xie, Tian-Peng;Xie, Sheng-Ming;Wang, Bang-Jin;Zhang, Jun-Hui;Yuan, Li-Ming. And the article was included in Chromatographia in 2020.Application of 695-06-7 This article mentions the following:

Porous organic cages (POCs) are an emerging class of porous mol. materials which self-assembled by discrete, shape-persistent, cage-like mols. and have recently received intensive interest in diverse fields. In this work, a hydroxyl-functionalized homochiral POC was synthesized by [4 + 6] condensation of 2-hydroxy-1,3,5-triformylbenzene with (1R, 2R)-diaminocyclohexane and coated on a capillary column for gas chromatog. (GC) separations Forty-one pairs of enantiomers belonging to various classes have been resolved on the column, including alcs., diols, esters, lactones, halohydrocarbons, ethers, epoxides, ketones and sulfoxides. Compared with β-cyclodextrin derivative-based com. β-DEX 120 column, previously reported chiral POCs- (CC9 and CC10) based columns, there are 12, 27 and 19 pairs of studied enantiomers cannot be resolved on β-DEX 120 column, CC9 column and CC10 column, resp. Besides, both separation factors and resolution values of some racemates are higher on this column than those on β-DEX 120 column, CC9 column and CC10 column. The results demonstrate that the column exhibits good chiral recognition complementarity or superior chiral resolution capability to those columns which used for comparison, and the introduction of hydroxyl group enhances hydrogen-bonding interaction to some racemates, leading to better enantioselectivity. The column also shows excellent separation performance toward positional isomers of dichlorobenzene, dibromobenzene, nitrotoluene, chlorotoluene, nitrobromobenzene and nitrochlorobenzene. The retention time and selectivity of analytes have no significant changes after more than 500 injections and 260°C conditioned for 6 h, showing the good repeatability and thermal stability of the column. This work indicates the promising prospect of POCs for GC separation, especially for the separation of enantiomers and also demonstrates the significance of design and synthesis of more functionalized chiral POCs for GC enantioseparation that broaden the enantiomer separation scope and applicability of POCs-based columns through their chiral recognition complementarities. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Application of 695-06-7).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) 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. 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.Application of 695-06-7

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

Reversible addition-fragmentation chain transfer polymerization of a typical hydrophobic monomer of styrene within microreactor of shell-corona hollow microspheres suspending in water was written by Zhang, Minchao;Zhang, Wangqing. And the article was included in Journal of Polymer Science, Part A: Polymer Chemistry in 2010.Related Products of 27249-90-7 This article mentions the following:

Reversible addition-fragmentation chain transfer (RAFT) polymerization of a typical hydrophobic monomer of styrene within microreactor of shell-corona hollow microspheres of poly(styrene-co-methacrylic acid) suspending in water is studied. The shell-corona hollow microspheres contain a hydrophilic corona of poly(methacrylic acid) (PMAA) and a crosslinked polystyrene shell, which can suspend in water because of the hydrophilic corona of PMAA. The size of the shell-corona hollow microspheres is about 289 nm and the extent of the microcavity of the hollow microsphere is 154 nm. These shell-corona hollow microspheres can act as microreactor, within which the typical hydrophobic monomer of styrene, the RAFT agent of S-benzyl dithiobenzoate and the initiator of 2,2′-azobisisobutyronitrile can be encapsulated and RAFT polymerization of styrene takes place in well controlled manner in water. It is found that the resultant polymer of polystyrene has a competitively low polydispersity index and its number-average mol. weight linearly increases with monomer conversion. The method is believed to be a new strategy of RAFT polymerization of hydrophobic monomer in aqueous solution © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Related Products of 27249-90-7).

Benzyl benzodithioate (cas: 27249-90-7) 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. 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.Related Products of 27249-90-7

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

Characterisation of the convective hot-air drying and vacuum microwave drying of Cassia alata: antioxidant activity, essential oil volatile composition and quality studies was written by Chua, Lisa Yen Wen;Chua, Bee Lin;Figiel, Adam;Chong, Chien Hwa;Wojdylo, Aneta;Szumny, Antoni;Lech, Krzysztof. And the article was included in Molecules in 2019.Related Products of 118-61-6 This article mentions the following:

The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC-MS anal. identified the presence of 51 volatiles, which were mostly present in all samples but with quant. variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g-1 db), 1-hexanol (18.70 mg 100 g-1 db) and salicylic acid (15.05 mg 100 g-1 db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g-1 db, and the major phytosterols present in fresh and dried samples were β-sitosterol (1162.24 mg 100 g-1 db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Related Products of 118-61-6).

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. 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.Related Products of 118-61-6

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

Efficient Synthesis of Dissymmetric Malonic Acid S,O-Esters via Monoalcoholysis of Symmetric Dithiomalonates under Neutral Conditions was written by Matsuo, Kazumasa;Shindo, Mitsuru. And the article was included in Organic Letters in 2011.Recommanded Product: 1190-39-2 This article mentions the following:

A novel method for the highly selective synthesis of dissym. S,O-malonates starting from sym. di-Ph dithiomalonates under neutral conditions is described. The key step is the thermal formation of an acylketene, the stability of which would contribute to the selectivity. The synthetic utility of the dissym. S,O-malonates is also shown. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Recommanded Product: 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) 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. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C 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: 1190-39-2

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

Synthesis of new Fe(II) and Ru(II) η⁵-monocyclopentadienyl compounds showing significant second order NLO properties was written by Valente, Andreia;Royer, Sophie;Narendra, Milan;Silva, Tiago J. L.;Mendes, Paulo J. G.;Robalo, M. Paula;Abreu, Manuel;Heck, Jurgen;Garcia, M. Helena. And the article was included in Journal of Organometallic Chemistry in 2013.Electric Literature of C8H4N2O This article mentions the following:

A series of new ruthenium(II) complexes of the general formula [Ru(η⁵-C₅H₅)(PP)(L)][PF₆] (PP = DPPE or 2PPh₃, L = 4-butoxybenzonitrile or N-(3-cyanophenyl)formamide) and the binuclear iron(II) complex [Fe(η⁵-C₅H₅)(PP)(μ-L)(PP)(η⁵-C₅H₅)Fe][PF₆]₂ (L = (E)-2-(3-(4-nitrophenyl)allylidene)malononitrile, that has been also newly synthesized) have been prepared and studied to evaluate their potential in the second harmonic generation property. All the new compounds were fully characterized by NMR, IR and UV-Vis spectroscopies and their electrochem. behavior was studied by cyclic voltammetry. Quadratic hyperpolarizabilities (β) of three of the complexes have been determined by hyper-Rayleigh scattering (HRS) measurements at fundamental wavelength of 1500 nm and the calculated static β₀ values are found to fall in the range 65-212 × 10^-30 esu. Compound presenting β₀ = 212 × 10^-30 esu has revealed to be 1.2 times more efficient than urea standard in the second harmonic generation (SHG) property, measured in the solid state by Kurtz powder technique, using a Nd:YAG laser (1064 nm). In the experiment, the researchers used many compounds, for example, 3-Cyanophenylisocyanate (cas: 16413-26-6Electric Literature of C8H4N2O).

3-Cyanophenylisocyanate (cas: 16413-26-6) 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. 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.Electric Literature of C8H4N2O

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

Volatile composition changes in lemon during fruit maturation by HS-SPME – GC – MS was written by Li, Chunxiu;Li, Xunlan;Liang, Guolu;Xiang, Suqiong;Han, Guohui. And the article was included in Journal of the Science of Food and Agriculture in 2022.HPLC of Formula: 105-87-3 This article mentions the following:

Volatiles are determinants of fruit aroma and flavor characteristics and also provide valuable information for lemon as ingredient for the food and drinks industry. Volatiles in ‘Eureka’ lemon and ‘Xiangshui’ lemon pulps from 130 to 186 days after flowering were enriched by headspace-solid-phase microextraction (HS-SPME), and analyzed by gas chromatog.-mass spectrometry (GC-MS). Seventy-seven volatiles of two lemon cultivars at the different ripening stages were identified and divided into six categories. Varieties and ripening stages had significant effects on individual volatiles in each category. The proportion of monoterpenes was found to be higher in ‘Eureka’ lemon, while ‘Xiangshui’ lemon had a higher proportion of sesquiterpenes, aldehydes and alcs. The proportion of monoterpene fluctuation decreased during fruit ripening, while fluctuation of sesquiterpenes, alcs., aldehydes and esters increased. Among the hydrocarbons, monoterpenes decreased their relative abundance from 91.67% to 81.04% in ‘Eureka’ lemon, and from 83.01% to 60.04% in ‘Xiangshui’ lemon; conversely, sesquiterpenes increased from 0.73% to 2.89% in ‘Eureka’ lemon, and from 3.21% to 8.48% in ‘Xiangshui’ lemon. Among the oxygenated volatiles, the proportions of alcs., aldehydes and esters were higher at 186 days after flowering in both two cultivars. The volatile organic compounds during fruit ripening of lemon varieties with different resistance were elucidated. The proportion of oxygenated volatiles increased during fruit ripening, and disease-resistant varieties had a higher proportion. These results provided important theor. support for the utilization of lemon fruits and the innovation of disease-resistant germplasm resources. 2021 Society of Chem. Industry. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3HPLC of Formula: 105-87-3).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) 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° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C 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. HPLC of Formula: 105-87-3

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

Cationic methacrylate polymers containing chiral amino acid moieties: controlled synthesis via RAFT polymerization was written by Kumar, Sonu;Roy, Saswati Ghosh;De, Priyadarsi. And the article was included in Polymer Chemistry in 2012.Safety of Benzyl benzodithioate This article mentions the following:

Two methacrylate containing amino acid based chiral monomers, Boc-L-alanine methacryloyloxyethyl ester (Boc-Ala-HEMA) and Boc-L-phenylalanine methacryloyloxyethyl ester (Boc-Phe-HEMA), were polymerized by the reversible addition-fragmentation chain transfer (RAFT) process to afford well-defined amino acid based polymers with controlled mol. weight, narrow mol. weight distribution, and precise chain end structure. Linear pseudo-first-order kinetics and number average mol. weight dependence on conversion were observed for the RAFT polymerizations Di-block copolymers were prepared by RAFT polymerization of Me methacrylate using poly(Boc-L-alanine methacryloyloxyethyl ester) or poly(Boc-L-phenylalanine methacryloyloxyethyl ester) as macro-chain transfer agents. Subsequent deprotection of the Boc group produced architectures with a primary amine moiety at the side chain, which showed pH responsiveness. The sp. rotations of both the chiral monomers and corresponding homo- and block copolymers were studied and alteration of sp. rotation due to transformation of monomer to polymer was noticed. In addition, the surface charge of various polymeric architectures was studied using dynamic light scattering (DLS) measurements. The self-assembly of block copolymer films was investigated by at. force microscopy (AFM). These pH-responsive cationic polymers can potentially be extended for the delivery of small interfering RNA. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Safety of Benzyl benzodithioate).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. 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.Safety of Benzyl benzodithioate

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

Ring opening reactions of 6-oxo-substituted spiro-pyrrolidinediones: synthesis of 4-substituted-1,5-dihydro-3-hydroxy-2-oxo-1,5-diphenyl-2H-pyrroles was written by Emerson, David W.;Titus, Richard L.;Mones, Marlon D.. And the article was included in Journal of Heterocyclic Chemistry in 1998.Formula: C9H12O4 This article mentions the following:

Reaction of 2-oxocycloalkylglyoxylate esters with N-phenylmethyleneaniline yields 2-aza-3,4,6-trioxo-1,2-diphenylspiro[4.n]alkanes. These undergo solvolytic opening of the oxocycloalkane ring to yield 4-substituted-1,5-dihydro-3-hydroxy-2-oxo-1,5-diphenyl-2H-pyrroles. In the experiment, the researchers used many compounds, for example, Ethyl 2-oxo-2-(2-oxocyclopentyl)acetate (cas: 39163-39-8Formula: C9H12O4).

Ethyl 2-oxo-2-(2-oxocyclopentyl)acetate (cas: 39163-39-8) 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. 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.Formula: C9H12O4

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

Probing the RAFT Process Using a Model Reaction between Alkoxyamine and Dithioester was written by Li, Changxi;He, Junpo;Liu, Ying;Zhou, Yanwu;Yang, Yuliang. And the article was included in Australian Journal of Chemistry in 2012.Product Details of 27249-90-7 This article mentions the following:

A small-mol. model reaction was designed to probe the reversible addition-fragmentation chain transfer (RAFT) process. In this reaction, alkoxyamine releases radicals that react in situ with dithioester through the RAFT process, generating new radicals through the fragmentation of the intermediate radical. The new radicals can be trapped by free 2,2,6,6-tetramethyl-piperidinyl-N-oxyl radicals (TEMPO) from homolysis of alkoxyamine. The overall reaction is the crossover of the leaving groups between alkoxyamine and dithioester. The advantage of this model as a probe of the RAFT process is that it does not involve polymerization-related elementary reactions such as initiation, propagation, and chain length dependent termination. The kinetics of the model reaction were measured using high-performance liquid chromatog., and then fitted by Monte Carlo simulation to estimate rate coefficients The obtained rate coefficients of addition for various dithioesters fell into a narrow range of 107-10⁸Lmol^-1s^-1, whereas the rate coefficient of fragmentation was model-dependent. It was also found that a significant fraction of the dithioester was consumed by an unspecified addnl. mechanism. A tentative explanation is proposed in which the intermediate radical undergoes a secondary RAFT reaction with dithioesters, forming a secondary intermediate that serves as a radical reservoir. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Product Details of 27249-90-7).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C 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. Product Details of 27249-90-7

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

Design of volatile organic compounds profiles of roasted Coffea arabica extracts produced by supercritical and conventional solvents was written by de Toledo, Paulo R. A. B.;de Melo, Marcelo M. R.;Rodrigues, Vitor H.;Pezza, Helena R.;Rocha, Silvia M.;Toci, Aline T.;Pezza, Leonardo;Portugal, Ines;Silva, Carlos M.. And the article was included in International Journal of Food Science and Technology in 2022.Safety of 5-Ethyldihydrofuran-2(3H)-one This article mentions the following:

This work addresses the potential of supercritical fluid extraction (SFE) to design volatile organic compounds (VOCs) profiles using roasted Coffea arabica. On the whole, 57 VOCs were identified by HS-SPME/GC-MS. A full factorial design was adopted to study the effect of pressure (180 and 300 bar), temperature (40 and 80°C) and ethanol content (0 and 5 weight%). The total extraction yield ranged from 1.4 weight% to 9.8 weight%. At 180 bar and 80°C, two extracts exhibited VOCs amount up to 3.5 times higher than the dichloromethane extract Temperature and pressure favored VOCs amount and total yield in conflicting ways, and ethanol had a negligible effect on VOCs amount At 180 bar and 80°C, the VOCs profile revealed a reinforcement of pyrroles, phenols, cyclopentenes and pyrans, at the expense of pyridines, carboxylic acids and furans. Hence, this essay evidences the potential of SFE to engineer coffee VOCs profiles. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Safety of 5-Ethyldihydrofuran-2(3H)-one).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C 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. Safety of 5-Ethyldihydrofuran-2(3H)-one

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