Tag: 300-400

Synthesis of tetrasubstituted symmetrical pyrazines from β-keto γ-amino esters: A mild strategy for self-dimerization of peptides was written by Ganesh Kumar, Mothukuri;Thombare, Varsha J.;Bhaisare, Rupal D.;Adak, Anindita;Gopi, Hosahudya N.. And the article was included in European Journal of Organic Chemistry in 2015.Safety of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate This article mentions the following:

A facile synthesis of highly sym. tetrasubstituted pyrazines through simple aerial oxidation of β-keto γ-amino esters is reported. The scope of the reaction was examined by use of various amino acid side-chain functional groups and peptides. The mild and efficient transformation of β-keto γ-amino esters into pyrazines may serve as an attractive strategy for self-dimerization of peptides. In the experiment, the researchers used many compounds, for example, (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9Safety of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate).

(S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9) 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 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 (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate

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

Probing α-Amino Aldehydes as Weakly Acidic Pronucleophiles: Direct Access to Quaternary α-Amino Aldehydes by an Enantioselective Michael Addition Catalyzed by Bronsted Bases was written by Garcia-Urricelqui, Ane;de Cozar, Abel;Mielgo, Antonia;Palomo, Claudio. And the article was included in Chemistry – A European Journal in 2021.COA of Formula: C16H24N2O4 This article mentions the following:

The chem. of α-amino aldehydes was expanded beyond their limits by documenting the first direct α-alkylation of α-branched α-amino aldehydes with nitroolefins. The reaction produced densely functionalized products bearing up to two, quaternary and tertiary, vicinal stereocenters with high diastereo- and enantioselectivity. DFT modeling lead to the proposal that intramol. hydrogen bonding between the NH group and the carbonyl oxygen atom in the starting α-amino aldehyde was key for reaction stereocontrol. In the experiment, the researchers used many compounds, for example, (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9COA of Formula: C16H24N2O4).

(S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9) 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. 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.COA of Formula: C16H24N2O4

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

S-Adamantyl Group Directed Site-Selective Acylation: Applications in Streamlined Assembly of Oligosaccharides was written by Blaszczyk, Stephanie A.;Xiao, Guozhi;Wen, Peng;Hao, Hua;Wu, Jessica;Wang, Bo;Carattino, Francisco;Li, Ziyuan;Glazier, Daniel A.;McCarty, Bethany J.;Liu, Peng;Tang, Weiping. And the article was included in Angewandte Chemie, International Edition in 2019.Product Details of 4163-60-4 This article mentions the following:

The site-selective functionalization of carbohydrates is an active area of research. Reported here is the surprising observation that the sterically encumbered adamantyl group directed site-selective acylation at the C2 position of S-glycosides through dispersion interactions between the adamantyl C-H bonds and the π system of the cationic acylated catalyst, which may have broad implications in many other chem. reactions. Because of their stability, chem. orthogonality, and ease of activation for glycosylation, the site-selective acylation of S-glycosides streamlines oligosaccharide synthesis and will have wide applications in complex carbohydrate synthesis. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Product Details of 4163-60-4).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) 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. 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 4163-60-4

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

An Efficient One-Pot Protocol for Direct Access to Diarylmethyl Thioglycosides with para-Quinone Methides via S -Glycosyl Isothiouronium Salts was written by Dubey, Atul;Mandal, Pintu Kumar. And the article was included in Synlett in 2020.Application of 4163-60-4 This article mentions the following:

An efficient one-pot protocol has been developed for the direct preparation of diarylmethyl thioglycosides starting from per-O-acetylated sugars via glycosyl isothiouronium salts. The one-pot reaction conditions involve rapid conversion of the per-O-acetylated sugar with thiourea in the presence of boron trifluoride etherate as catalyst to give the corresponding glycosyl isothiouronium salt, which is subsequently treated with a para-quinone methide in the presence of a base to give the a diarylmethyl thioglycoside in excellent yield. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Application of 4163-60-4).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) 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 4163-60-4

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

Determination of phthalic acid esters and di(2-ethylhexyl) adipate in coffee obtained from capsules was written by Dominguez-Hernandez, Cristopher;Ortega-Zamora, Cecilia;Gonzalez-Salamo, Javier;Hernandez-Borges, Javier. And the article was included in Food Chemistry in 2022.Category: esters-buliding-blocks This article mentions the following:

In this work, the ammonium formate version of the QuEChERS method has been applied for the first time to the extraction of a group of nine phthalic acid esters and one adipate from three types of coffee (maximum intensity, intermediate intensity and decaffeinated) prepared from coffee capsules, using gas chromatog. coupled to mass spectrometry for analytes separation and determination Matrix-matched calibration showed good linearity with determination coefficients (R2) higher than 0.9983 for all analytes and matrixes. In general, matrix effect assessment revealed a medium effect of signal suppression, while mean relative recovery values were in the range 70-120% with relative standard deviation values ≤19% for most analytes. Several samples of each type of coffee obtained from capsules made of different materials were also analyzed, finding concentrations of DBP, DEHA and DEHP in the range 29.3-734 ng/capsule, below the tolerable daily intake established for some of them. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Category: esters-buliding-blocks).

Dicyclohexyl phthalate (cas: 84-61-7) 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. 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. Category: esters-buliding-blocks

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

Steady-State Based Model of Airborne Particle/Gas and Settled Dust/Gas Partitioning for Semivolatile Organic Compounds in the Indoor Environment was written by Li, Hai-Ling;Yang, Pu-Fei;Liu, Li-Yan;Gong, Bei-Bei;Zhang, Zi-Feng;Ma, Wan-Li;Macdonald, Robie W.;Nikolaev, Anatoly N.;Li, Yi-Fan. And the article was included in Environmental Science & Technology in 2022.Name: Dicyclohexyl phthalate This article mentions the following:

Indoor semivolatile organic compounds (SVOCs), present in the air, airborne particles, settled dust, and other indoor surfaces, can enter the human body through several pathways. Knowing the partitioning between gaseous and particulate phases is important in identifying specific pathway contributions and thereby accurately assessing human exposure. Numerous studies have developed equilibrium equations to predict airborne particle/gas (P/G) partitioning in air (K_P) and dust/gas (D/G) partitioning in settled dust (K_D). The assumption that P/G and D/G equilibrium are instantaneous for airborne and settled dust phases, commonly adopted by current indoor fate models, is not likely valid for compounds with high octanol-air partition coefficients (K_OA). Here, we develop steady-state based equations to predict K_P and K_D in the indoor environment. Results show that these equations perform well and are verified by worldwide monitoring data. It is suggested that instantaneous steady state could work for P/G and D/G partitioning of SVOCs in indoor environments, and the equilibrium is just a special case of the steady state when log K_OA < 11.38 for P/G partitioning and log K_OA < 10.38 for D/G partitioning. These newly developed equations and methods provide a tool for more accurate assessment for human exposure to SVOCs in the indoor environment. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Name: Dicyclohexyl phthalate).

Dicyclohexyl phthalate (cas: 84-61-7) 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. 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. Name: Dicyclohexyl phthalate

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

Contaminant occurrence, mobility and ecological risk assessment of phthalate esters in the sediment-water system of the Hangzhou Bay was written by Wang, Liu-Yong;Gu, Yan-Yu;Zhang, Ze-Ming;Sun, Ai-Li;Shi, Xi-Zhi;Chen, Jiong;Lu, Yin. And the article was included in Science of the Total Environment in 2021.Name: Dicyclohexyl phthalate This article mentions the following:

The pollution characteristics, spatiotemporal variation, sediment-water partitioning, and potential ecol. risk assessment of phthalate esters (PAEs) in the sediment-seawater system of the Hangzhou Bay (HZB) in summer and autumn were researched. The sum of the concentrations of the 10 PAEs in seawater ranges from 7305 ng/L to 22,861 ng/L in summer and from 8100 ng/L to 33,329 ng/L in autumn, with mean values of 15,567 ± 4390 and 17,884 ± 6850 ng/L, resp. The Σ16PAEs in the sediments are between 118 and 5888μg/kg and 145 and 4746μg/kg in summer and autumn, resp. The level of PAEs in seawater varies with the seasons, but it is relatively stable in the sediments. Di(2-ethylhexyl) phthalate (DEHP), di-Bu phthalate (DnBP), and diisobutyl phthalate (DiBP) are the predominant PAE congeners in the HZB. The DnBP and DiBP concentrations in seawater are greater than the DEHP concentration, which is the opposite in the sediments. The sediment-seawater equilibrium distribution study indicates that the PAEs with medium mol. weights, such as DiBP, Bu benzyl phthalate, and DnBP, are near dynamic equilibrium in the sediment-seawater system; PAEs with high mol. weights (e.g., di-n-octyl phthalate and DEHP) tend to transfer from water to the sediments; and PAEs with low mol. weights (e.g., di-Me phthalate, di-Et phthalate, and diamyl phthalate) tend to spread to seawater. The risk assessment results in seawater indicate that DEHP and DiBP might pose high potential risks to sensitive organisms, and DnBP might exhibit medium ecol. risks. In the sediment, DiBP might display a high potential risk to fish, and the potential risk of DEHP is high in several sites. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Name: Dicyclohexyl phthalate).

Dicyclohexyl phthalate (cas: 84-61-7) 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. Name: Dicyclohexyl phthalate

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

Quality assessment of environmental water by a simple and fast non-ionic hydrophobic natural deep eutectic solvent-based extraction procedure combined with liquid chromatography tandem mass spectrometry for the determination of plastic migrants was written by Santana-Mayor, Alvaro;Socas-Rodriguez, Barbara;Rodriguez-Ramos, Ruth;Herrera-Herrera, Antonio V.;Rodriguez-Delgado, Miguel Angel. And the article was included in Analytical and Bioanalytical Chemistry in 2021.Safety of Dicyclohexyl phthalate This article mentions the following:

A non-ionic hydrophobic natural deep eutectic solvent (HNADES) based on thymol and menthol was proposed for the liquid-liquid microextraction of fourteen phthalates and one adipate from environmental water samples. Separation, identification, and quantification were achieved by ultra-high-performance liquid chromatog. coupled to tandem mass spectrometry. The main factors affecting the extraction efficiency were thoroughly studied. Sample pH of 8 and 100 μL of thymol:menthol at molar ratio 2:1 were selected as the best conditions, while ionic strength and type of dispersant solvent were not relevant for the extraction of the target compounds The whole methodol. was validated for treated wastewater, runoff, and pond water matrixes, using di-Bu phthalate-3,4,5,6-d4 and dihexyl phthalate-3,4,5,6-d4 as surrogates. Recovery ranged from 70 to 127% with relative standard deviation values lower than 14%. Limits of quantification of the method were in the range 0.042-0.425 μg/L for treated wastewater, 0.015-0.386 μg/L for runoff, and 0.013-0.376 μg/L for pond water. The methodol. was applied for the anal. of real treated wastewater, runoff, and pond water samples from different places of Tenerife and Gran Canaria (Canary Islands) finding the presence of di-Et phthalate, diallyl phthalate, di-Pr phthalate, benzylbutyl phthalate, di-Bu phthalate, bis-(2-n-butoxyethyl) phthalate, di-n-pentyl phthalate, dicyclohexyl phthalate, and bis-(2-ethylhexyl) phthalate at concentrations between 105.2 and 3414 ng/L. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Safety of Dicyclohexyl phthalate).

Dicyclohexyl phthalate (cas: 84-61-7) 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.Safety of Dicyclohexyl phthalate

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

Assembly of Divalent Ligands and Their Effect on Divalent Binding to Pseudomonas aeruginosa Lectin LecA was written by Yu, Guangyun;Vicini, Anna Chiara;Pieters, Roland J.. And the article was included in Journal of Organic Chemistry in 2019.Name: (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate This article mentions the following:

Divalent ligands were prepared as inhibitors for the adhesion protein of the problematic Pseudomonas aeruginosa pathogen. Bridging two binding sites enables simultaneous binding of two galactose moieties which strongly enhances binding. An alternating motif of glucose and triazole and aryl groups was shown to have the right mix of rigidity, solubility and ease of synthesis. Spacers were varied with respect to the core unit as well as the aglycon portions, to optimize dynamics and enhance interactions with the protein. Affinities of the divalent ligands were measured by ITC and Kd’s as low as 12 nM were determined, notably for a com-pounds with either a rigid (phenyl) or flexible (butyl) unit at the core. Introducing a Ph aglycon moiety next to the galactoside ligands on both termini did indeed lead to a higher enthalpy of binding which was more than compensated by entropic costs. The results were discussed in terms of thermodn. and theor. calculations of the expected and observed multivalency effects. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Name: (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) 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. 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.Name: (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate

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

Genomic and hormonal biomarkers of phthalate induced male rat reproductive developmental toxicity part II: a targeted RT-qPCR array approach that defines a unique adverse outcome pathway was written by Gray, Leon Earl Jr.;Lambright, Christy S.;Conley, Justin M.;Evans, Nicola;Furr, Johnathan R.;Hannas, Bethany R.;Wilson, Vickie S.;Sampson, Hunter;Foster, Paul M. D.. And the article was included in Toxicological Sciences in 2021.COA of Formula: C20H26O4 This article mentions the following:

Previously, we demonstrated that exposure to some diortho-phthalate esters during sexual differentiation disrupts male reproductive development by reducing fetal rat testis testosterone production (T Prod) and gene expression in a dose-related manner. The objectives of the current project were to expand the number of test compounds that might reduce fetal T Prod, including phthalates, phthalate alternatives, pesticides, and drugs, and to compare reductions in T Prod with altered testis mRNA expression. We found that PEs that disrupt T Prod also reduced expression of a unique “cluster” of mRNAs for about 35 genes related to sterol transport, testosterone and insulin-like hormone 3 hormone syntheses, and lipoprotein signaling and cholesterol synthesis. However, phthalates had little or no effect on mRNA expression of genes in peroxisome proliferator-activated receptor (PPAR) pathways in the fetal liver, whereas the 3 PPAR agonists induced the expression of mRNA for multiple fetal liver PPAR pathway genes without reducing testis T Prod. In summary, phthalates that disrupt T Prod act via a novel adverse outcome pathway including down regulation of mRNA for genes involved in fetal endocrine function and cholesterol synthesis and metabolism This profile was not displayed by PEs that did not reduce T Prod, PPAR agonists or the other chems. Reductions in fetal testis gene expression and T Prod in utero can be used to establish relative potency factors that can be used quant. to predict the doses of individual PEs and mixtures of phthalates that produce adverse reproductive tract effects in male offspring. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7COA of Formula: C20H26O4).

Dicyclohexyl phthalate (cas: 84-61-7) 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. 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.COA of Formula: C20H26O4

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