Tag: 200-300

Effects of shielding of the carbonyl group in the alkaline hydrolysis of monoalkyl-substituted diethyl malonates was written by Kamalov, G. L.;Tishchenko, O. I.;Lozitskaya, R. N.. And the article was included in Voprosy Stereokhimii in 1972.Related Products of 10203-58-4 This article mentions the following:

Rate constants and activation parameters were determined for the 1st and 2nd hydrolysis steps of RCH(CO2Et)2 (I; R = H, Me, Et, Pr, Me2CH, Me2CHCH2) at 25, 35, and 45°. Taft correlations were successful after arranging I in 2 groups, one without R = H, the other without R = Me2CH. From the correlation equations the effects of mesomeric and polar shielding of the carbonyl groups in both hydrolysis steps were determined In the 1st step, increasing the size of R lowered the C-H acidity of I and thus increased the hydrolysis rate. In the 2nd step, increasing the size of R lowered the screening effect of the CO2- group on the reaction center and this also increased the hydrolysis rate. In the experiment, the researchers used many compounds, for example, Diethyl isobutylmalonate (cas: 10203-58-4Related Products of 10203-58-4).

Diethyl isobutylmalonate (cas: 10203-58-4) 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. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Related Products of 10203-58-4

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

A Cocktail of Industrial Chemicals in Lipstick and Nail Polish: Profiles and Health Implications was written by Tang, Shuqin;Chen, Yukun;Song, Guixian;Liu, Xiaotu;Shi, Yumeng;Xie, Qitong;Chen, Da. And the article was included in Environmental Science & Technology Letters in 2021.Application of 106-79-6 This article mentions the following:

Beauty products contain various industrial chems. to increase their functionality and appearance. The frequent use of beauty products may increase human exposure to industrial chems., but to date, their chem. components remain poorly characterized. Our work characterized the chem. components in lipstick and nail polish by screening for a total of 231 chems. from seven categories, including organophosphate esters (OPEs), phthalate esters (PAEs), non-PAE plasticizers, bisphenol analogs, parabens, UV stabilizers, and antioxidants. Their total concentrations ranged from 38.9 to 3810 μg/g (median of 193 μg/g) and from 18.6 to 1910 μg/g (307 μg/g) in lipstick (n = 34) and nail polish (n = 15), resp. The chem. compositions differed between lipstick and nail polish, but non-PAE plasticizers generally dominated over other groups of chems. A number of emerging plasticizers, OPEs, and UV stabilizers have rarely been reported in personal care products or environmental samples but were found at very high levels in beauty products, raising concern about their environmental release and human exposure risk. Although the employment of a hazard quotient approach suggested low health risks for exposure to industrial chems. from the use of beauty products, potential mixture effects from the chem. cocktail and occupational exposure to beauty products should not be overlooked. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Application of 106-79-6).

Dimethyl decanedioate (cas: 106-79-6) 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. Application of 106-79-6

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

Synthesis and characterization of tin oxide-modified mesoporous SBA-15 molecular sieves and catalytic activity in trans-esterification reaction was written by Shah, Pallavi;Ramaswamy, Arumugamangalam V.;Lazar, Karoly;Ramaswamy, Veda. And the article was included in Applied Catalysis, A: General in 2004.Reference of 1190-39-2 This article mentions the following:

Mesoporous silica mol. sieve SBA-15 has been synthesized and incorporated with various amounts of tin via incipient-wetness impregnation using tin chloride in ethanol followed by calcination. Characterization was done by x-ray fluorescence spectrophotometry (XRF), powder x-ray diffraction (PXRD), nitrogen adsorption, diffuse reflectance UV (DRUV), scanning and transmission electron microscopy (SEM, TEM), FTIR, ²⁹Si and ¹¹⁹Sn MAS NMR, and Sn-Moessbauer spectroscopic techniques to understand the chem. nature of incorporated tin. The silanol groups on the internal walls of SBA-15 are suggested to be the sites for tin incorporation. Bulk structural characterization techniques (x-ray diffraction and BET) are used to demonstrate that the hexagonal structure is maintained during impregnation. Tin oxide exists as a thin film anchored inside the mesopores of SBA-15. Complementarily, ¹¹⁹Sn NMR and Moessbauer spectroscopies are used to investigate the microstructure of the Sn centers grafted to the mesoporous walls. Sn-Moessbauer spectroscopic studies reveal that Sn²⁺ may form upon reductive treatments and can probably be stabilized atomically in the pore wall, whereas Sn⁴⁺ is stabilized as large entities. While SBA-15 itself shows some activity in transesterification of di-Et malonate with various alcs., Sn-SBA-15 samples are found to possess enhanced catalytic activity for the same. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Reference of 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 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.Reference of 1190-39-2

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

Prenatal Exposure to Emerging Plasticizers and Synthetic Antioxidants and Their Potency to Cross Human Placenta was written by Tang, Shuqin;Sun, Xiangfei;Qiao, Xinhang;Cui, Wenxuan;Yu, Feixiang;Zeng, Xiaowen;Covaci, Adrian;Chen, Da. And the article was included in Environmental Science & Technology in 2022.SDS of cas: 106-79-6 This article mentions the following:

Gestational exposure to environmental chems. and subsequent permeation through the placental barrier represents potential health risks to both pregnant women and their fetuses. In the present study, we explored prenatal exposure to a suite of 46 emerging plasticizers and synthetic antioxidants (including five transformation products of 2,6-di-tert-butyl-4-hydroxytoluene, BHT) and their potency to cross human placenta based on a total of 109 maternal and cord serum pairs. Most of these chems. have rarely or never been investigated for prenatal exposure and associated health risks. Eleven of them exhibited detection frequency greater than 50% in maternal blood, including di-Bu fumarate (DBF), 2,6-di-tert-butylphenol (2,4-DtBP), 1,3-diphenylguanidine (DPG), methyl-2-(benzoyl)benzoate (MBB), tri-Et citrate (TEC), BHT, and its five metabolites, with a median concentration from 0.05 to 3.1 ng/mL. The transplacental transfer efficiency (TTE) was determined for selected chems. with valid measurements in more than 10 maternal/cord blood pairs, and the mean TTEs exhibited a large variation (i.e., 0.29-2.14) between chems. The determined TTEs for some of the target chems. were comparable to the predicted values by our previously proposed models developed from mol. descriptors, indicating that their transplacental transfer potency could be largely affected by physicochem. properties and mol. structures. However, addnl. biol. and physiol. factors may influence the potency of environmental chems. to cross human placenta. Overall, our study findings raise concern on human exposure to an increasing list of plastic additives during critical life stages (e.g., pregnancy) and potential health risks. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6SDS of cas: 106-79-6).

Dimethyl decanedioate (cas: 106-79-6) 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. 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.SDS of cas: 106-79-6

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

Mixed [2.2]Cyclophanes of Pyrene and Benzene was written by Vermeij, Rudolf J.;Miller, David O.;Dawe, Louise N.;Aprahamian, Ivan;Sheradsky, Tuvia;Rabinovitz, Mordecai;Bodwell, Graham J.. And the article was included in Australian Journal of Chemistry in 2010.Safety of Dimethyl 5-ethynylisophthalate This article mentions the following:

An examination of the literature on [2.2]cyclophanes reveals a loose relationship between the relative sizes of the two half-cyclophanes’ (as measured by the parameter Δd) and the limitations of the dominant general synthetic approaches. Direct coupling methods tend to be successful only for systems with Δd values below 1.0Å, whereas ring-contraction-based approaches are usually viable for systems with Δd values up to 2.0 Å. For the very few known systems with Δd values greater than 2.0 Å, aromatization-based approaches are the only ones that have been successful. The syntheses of two [2.2]cyclophanes with very large Δd values, [2]para-cyclo[2](2,7)pyrenophane (17) (Δd=4.25 Å) and [2]meta-cyclo[2](2,7)pyrenophane (18) (Δd=5.04 Å) are presented here. The syntheses hinge on a valence isomerization/dehydrogenation reaction. The crystallog. determined bend angle, θ, for 18 is 96.1°. Cyclophane 18 undergoes a degenerate conformational flip, the energy barrier for which was determined to be 18.9 kcalmol^-1 by DNMR. In the experiment, the researchers used many compounds, for example, Dimethyl 5-ethynylisophthalate (cas: 313648-56-5Safety of Dimethyl 5-ethynylisophthalate).

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

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

Synthesis of cyclic and acyclic partial retro-inverso modified enkephalins was written by Berman, Judd M.;Goodman, Murray. And the article was included in International Journal of Peptide & Protein Research in 1984.Synthetic Route of C11H20O4 This article mentions the following:

Title acyclic peptides H-Tyr-D-Ala-Gly-gPhe-R,S-mLeu-NH₂.CF₃CO₂H (the g prefix represents the corresponding gem-diaminoalkyl residue and the m prefix represents the corresponding malonic acid derivative), H-Tyr-D-Ala-Gly-gPhe-D-Leu-For.CF₃CO₂H (For = formyl), and H-Tyr-D-Ala-Gly-Phe-gLeu-For and title cyclic peptides I, II, and III were prepared by conventional solution methods. gem-Diaminoalkyl residues were prepared by treating protected dipeptide amides with (CF₃CO₂)₂IPh; thus, Boc-Gly-Phe-NH₂ (Boc = Me₃CO₂C) was treated with (CF₃CO₂)₂IPh to give 80% Boc-Gly-gPhe-H.CF₃CO₂H. HO-R,S-mLeu-NH₂ and HO-R,S-mLeu-OCH₂Ph were prepared from Me₂CHCH₂CH(CO₂Et)₂. Cyclizations were achieved at high dilution using diphenylphosphoryl azide (IV) as coupling agent. Thus, Boc-Tyr(CMe₃)-D-Glu-Gly-gPhe-D-Leu-H was cyclized by IV at high dilution in DMF containing Et₃N to give 27% protected cyclic peptide, which was deblocked by CF₃CO₂H/anisole to give I. 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 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.Synthetic Route of C11H20O4

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

Alkylation of active methylene compounds with alcohols catalyzed by an iridium complex. [Erratum to document cited in CA147:322401] was written by Morita, Masao;Obora, Yasushi;Ishii, Yasutaka. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2007.Reference of 1190-39-2 This article mentions the following:

The authors accidentally missed citing two recent publications related to their work. The Reference 3(a) should read: “P. A. Slatford, M.K. Whittlesey and J.M.J. Williams, Tetrahedron Lett., 2006, 47, 6787.”. Reference 3(b) should read: “P.J. Black, G. Cami-Kobeci, M.G. Edwards, P.A. Slatford, M.K. Whittlesey and J.M.J. Williams, Organic Biomol. Chem., 2006, 4, 116.”. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Reference of 1190-39-2).

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. 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 1190-39-2

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

Azidobarbiturates. Part I. Synthesis of barbituric acid derivatives containing an azido group up in the 5th position was written by Toth, G.;Makleit, S.. And the article was included in Acta Chimica Academiae Scientiarum Hungaricae in 1981.Application of 10203-58-4 This article mentions the following:

Azidobarbiturates I (R = Me, Et, Bu, CHMeEt, CH₂CHMe₂, Ph, R¹ = H; R = Me, Bu, CHMeEt, R¹ = Me; R = Et, CHMeEt, R¹ = Ph) were prepared by treating the bromobarbiturates with NaN₃. I (R = Bu, R¹ = H, Me) were also obtained by brominating BuCH(CO₂Et)₂, treating BuCBr(CO₂Et)₂ with NaN₃, and cyclizing BuCN₃(CO₂Et)₂ with R¹NHCONH₂. In the experiment, the researchers used many compounds, for example, Diethyl isobutylmalonate (cas: 10203-58-4Application of 10203-58-4).

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.Application of 10203-58-4

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

Silica gel chemically bonded with polyacrylamide via thiol-ene click chemistry as stationary phase material for hydrophilic interaction liquid chromatography was written by Yang, Duo;Yu, Dong-ping;Dong, Xue-fang;Shen, Ai-jin;Jin, Gao-wa;Guo, Zhi-mou;Yan, Jing-yu;Liu, Ming-yang;Liang, Xin-miao. And the article was included in Fenxi Huaxue in 2015.Computed Properties of C14H12S2 This article mentions the following:

Thiol-ene click chem. was applied to immobilize poly-acrylamide onto thiol-modified silica gel to prepare a novel stationary phase for hydrophilic interaction liquid chromatog. Polymer was synthesized by reversible addition-fragmentation chain transfer reaction of acrylamide and benzyl benzodithioate. Alkenyl functionalities were introduced onto the silica gel by the reaction of 3-isocyanatopropyltrimethoxysilane, allylamine and pyridine in toluene, and then the product was reacted with silica gel. The thiol-modified silica gel reacted with the poly-acrylamide prepared in methanol at 55°C for 48 h in the presence of 2,2-azo two iso-Bu amidine hydrochloride to give a novel stationary phase for hydrophilic interaction liquid chromatog. By using characterization method of elemental anal. and IR spectroscopy, compared with ethylene urea silica (EUS), the carbon content increased, and multiple amide IR characteristic peaks existed at 1636 cm^-1 and 1570 cm^-1. The effects of water content, salt concentration and pH of mobile phase on the retention time of polar compound were investigated. The results showed that with the increase of water content, retention time decreased; neural and basic compounds increases with the increasing salt concentration; and basic compounds decreased with the decrease of pH in the pH 3.3-4.8 range, which were both in contrast with the acid compounds The better successful separation of nucleosides and glycosides was obtained by the novel stationary phase compared with traditional stationary phase of silica gel, illustrating great potential of the stationary phase in the separation of polar compounds In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Computed Properties of C14H12S2).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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.Computed Properties of C14H12S2

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

Biomimetic Asymmetric Reduction of Tetrasubstituted Olefin 2,3-Disubstituted Inden-1-ones with Chiral and Regenerable NAD(P)H Model CYNAM was written by Zhu, Zhou-Hao;Ding, Yi-Xuan;Wu, Bo;Zhou, Yong-Gui. And the article was included in Organic Letters in 2021.Quality Control of malonic acid dibutyl ester This article mentions the following:

Because of the formidable development of the asym. reduction of tetrasubstituted olefins, an effective method is in urgent demand. Herein, through the biomimetic protocol of the coenzyme NAD(P)H, the reduction of tetrasubstituted olefin 2,3-substituted 1H-inden-1-ones has been successfully realized with the catalytic chiral NAD(P)H model CYNAM, which is hard to bring about via the common rhodium or iridium-based catalytic system, producing the corresponding products in good yield (up to 98%) with good enantioselectivity (up to 99% ee). Furthermore, the chiral bioactive mol. can be concisely synthesized from the reduced product. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Quality Control of malonic acid dibutyl ester).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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. Quality Control of malonic acid dibutyl ester

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