Tag: 200-300

¹H NMR determination of 1,3-dicyclohexylurea, glutaric acid and triethylamine in medical four-arm poly(ethylene glycol)-N-hydroxysuccinimide-glutarate for better quality control was written by Li, Fei-Fei;Liu, Hui-Xiang;Zhang, Yan-Li;Wang, Shu-Qi. And the article was included in Analytical Methods in 2019.Application In Synthesis of 1,3-Dicyclohexylurea This article mentions the following:

Absorbable vascular sealing medical glue, which belongs to Class III medical devices, is a special new material for preventing the leakage of cerebrospinal fluid. Medical four-arm poly(ethylene glycol)-N-hydroxysuccinimide-glutarate (4-arm-PEG-SG) with a mol. weight of 20 000 is the main component of the absorbable medical glue. According to its quality standard, the quality control of residues 1,3-dicyclohexylurea (DCU), glutaric acid (GA) and triethylamine (TEA) is required. A rapid anal. method of quant. ¹H NMR (¹H NMR) for the determination of residues DCU, GA and TEA in medical 4-arm-PEG-SG was established in the present study. The peaks at δ 1.56 (4H, m), δ 2.71 (4H, t, J = 6.7 Hz), and δ 2.42 (6H, q, J = 7.2 Hz) were selected for quantifying DCU, GA and TEA, resp., with deuterated pyridine as the solvent and tetramethylsilane as the internal standard The ¹H NMR assay was validated by several exptl. parameters including specificity, linearity, accuracy, precision, robustness, limit of detection (LOD), limit of quantification (LOQ) and stability. The average recoveries obtained were in the range of 99.48-102.02% for all three residues. Compared with the HPLC and GC approaches, the proposed ¹H NMR method proved to be a powerful tool for quantification due to its unique advantages of simplicity, rapidity and high robustness, especially not requiring standard compounds for calibration curve preparation In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Application In Synthesis of 1,3-Dicyclohexylurea).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Amides include many other important biological compounds, as well as many drugs like paracetamol, penicillin and LSD. Low-molecular-weight amides, such as dimethylformamide, are common solvents. In simple aromatic amides, fragmentation occurs on both sides of the carbonyl group. If a hydrogen is available in N-substituted aromatic amides, it tends to migrate and form an aromatic amine and the loss of a ketene.Application In Synthesis of 1,3-Dicyclohexylurea

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

Multi stage peroxide and activated peroxide bleaching of kenaf bast pulp was written by Zeinaly, Farhad;Shakhes, Jalal;Zeinali, Nooshin. And the article was included in Carbohydrate Polymers in 2013.Safety of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) This article mentions the following:

Soda-anthraquinone kenaf bast pulp (12.5 kappa number and 32% ISO brightness) has been bleached with multi stage peroxide bleaching process. Bleaching process was carried out in different sequences of peroxide stage without and with activator (tetraacetylethylenediamine, TAED) to about 80% ISO brightness. Full bleached pulp production with high brightness and viscosity and also, low COD and no adsorbable organic halogens (AOX) in effluent are the aims of this study. The effects of temperature, retention time, chem. charges, TAED/peroxide ratio and alkalinity have been studied in order to maximize the brightness gain at the lowest viscosity loss. H₂O₂ was activated as bleaching agent under milder conditions, such as low alkalinity or low temperature, by TAED activator. Therefore, TAED charge caused to an improvement in viscosity, pulp yield and effluent COD load. Pre-treatment with EDTA for 30 min and in acidic condition gave 2-4% gain in ISO brightness. In the experiment, the researchers used many compounds, for example, N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4Safety of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide)).

N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4) belongs to amides. Amides can be viewed as a derivative of a carboxylic acid RC(=O)OH with the hydroxyl group –OH replaced by an amine group −NR′R″; or, equivalently, an acyl (alkanoyl) group RC(=O)− joined to an amine group. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Safety of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide)

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

One-pot sequential 1,2-addition, Pd-catalysed cross-coupling of organolithium reagents with Weinreb amides was written by Giannerini, M.;Vila, C.;Hornillos, V.;Feringa, B. L.. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2016.COA of Formula: C9H10BrNO2 This article mentions the following:

An efficient sequential 1,2-addition/cross-coupling of Weinreb amides with two organolithium reagents is reported. This synthetic approach allows access to a wide variety of functionalized ketones in a modular way. The one-pot procedure presented here takes advantage of a kinetically stable tetrahedral Weinreb intermediate during subsequent Pd-catalyzed cross-coupling with the second organolithium reagent leading, within short reaction times and under mild conditions, to the formation of ketones in excellent overall yields. In the experiment, the researchers used many compounds, for example, 4-Bromo-N-methoxy-N-methylbenzamide (cas: 192436-83-2COA of Formula: C9H10BrNO2).

4-Bromo-N-methoxy-N-methylbenzamide (cas: 192436-83-2) belongs to amides. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. In simple aromatic amides, fragmentation occurs on both sides of the carbonyl group. If a hydrogen is available in N-substituted aromatic amides, it tends to migrate and form an aromatic amine and the loss of a ketene.COA of Formula: C9H10BrNO2

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

Physical and enzymatic properties of a new manganese peroxidase from the white-rot fungus Trametes pubescens strain i8 for lignin biodegradation and textile-dyes biodecolorization was written by Rekik, Hatem;Zarai Jaouadi, Nadia;Bouacem, Khelifa;Zenati, Bilal;Kourdali, Sidali;Badis, Abdelmalek;Annane, Rachid;Bouanane-Darenfed, Amel;Bejar, Samir;Jaouadi, Bassem. And the article was included in International Journal of Biological Macromolecules in 2019.Related Products of 10543-57-4 This article mentions the following:

A new manganese peroxidase-producing white-rot basidiomycete fungus was isolated from symptomatic wood of the camphor trees Cinnamomum camphora (L.) at the Hamma Botanical Garden (Algeria) and identified as Trametes pubescens strain i8. The enzyme was purified (MnP TP55) to apparent electrophoretic homogeneity and biochem. characterized. The specific activity and Reinheitzahl value of the purified enzyme were 221 U/mg and 2.25, resp. MALDI-TOF/MS anal. revealed that the purified enzyme was a monomer with a mol. mass of 55.2 kDa. The NH₂-terminal sequence of the first 26 amino acid residues of MnP TP55 showed high similarity with those of white-rot fungal peroxidases. It revealed optimal activity at pH 5 and 40 °C. This peroxidase was completely inhibited by sodium azide and potassium cyanide, suggesting the presence of heme-components in its tertiary structure. Interestingly, MnP TP55 showed higher catalytic efficiency, organic solvent-tolerance, dye-decolorization ability, and detergent-compatibility than that of horseradish peroxidase (HRP) from roots of Armoracia rustanica, manganese peroxidase from Bjerkandera adusta strain CX-9 (MnP BA30), and manganese peroxidase from Phanerochaete chrysosporium (MnP PC). Overall, the findings provide strong support for the potential candidacy of MnP TP55 for environmental applications, mainly the development of enzyme-based technologies for lignin biodegradation, textile-dyes biodecolorization, and detergent formulations. In the experiment, the researchers used many compounds, for example, N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4Related Products of 10543-57-4).

N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4) belongs to amides. Amides include many other important biological compounds, as well as many drugs like paracetamol, penicillin and LSD. Low-molecular-weight amides, such as dimethylformamide, are common solvents. The presence of the amide group –C(=O)N– is generally easily established, at least in small molecules. It can be distinguished from nitro and cyano groups in IR spectra. Amides exhibit a moderately intense νCO band near 1650 cm−1. By 1H NMR spectroscopy, CONHR signals occur at low fields. In X-ray crystallography, the C(=O)N center together with the three immediately adjacent atoms characteristically define a plane.Related Products of 10543-57-4

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

An α-Cyclopropanation of Carbonyl Derivatives by Oxidative Umpolung was written by Bauer, Adriano;Di Mauro, Giovanni;Li, Jing;Maulide, Nuno. And the article was included in Angewandte Chemie, International Edition in 2020.Application In Synthesis of 4-Bromo-N-methoxy-N-methylbenzamide This article mentions the following:

The reactivity of iodine(III) reagents towards nucleophiles is often associated with umpolung and cationic mechanisms. Herein, we report a general process converting a range of ketone derivatives into α-cyclopropanated ketones by oxidative umpolung [e.g., I → II (71%, d.r. > 95:5) + III (8%, d.r. > 95:5) in presence of PhIO.MsOH and BF₃.OEt₂]. Mechanistic investigation and careful characterization of side products revealed that the reaction follows an unexpected pathway and suggests the intermediacy of non-classical carbocations. In the experiment, the researchers used many compounds, for example, 4-Bromo-N-methoxy-N-methylbenzamide (cas: 192436-83-2Application In Synthesis of 4-Bromo-N-methoxy-N-methylbenzamide).

4-Bromo-N-methoxy-N-methylbenzamide (cas: 192436-83-2) belongs to amides. In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well. Thus amides can participate in hydrogen bonding with water and other protic solvents; the oxygen atom can accept hydrogen bonds from water and the N–H hydrogen atoms can donate H-bonds. As a result of interactions such as these, the water solubility of amides is greater than that of corresponding hydrocarbons. These hydrogen bonds are also have an important role in the secondary structure of proteins.Application In Synthesis of 4-Bromo-N-methoxy-N-methylbenzamide

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

Chiral, Magnetic, and Photosensitive Liquid Crystalline Nanocomposites Based on Multifunctional Nanoparticles and Achiral Liquid Crystals was written by Poryvai, Anna;Smahel, Michal;Svecova, Marie;Nemati, Ahlam;Shadpour, Sasan;Ulbrich, Pavel;Ogolla, Timothy;Liu, Jiao;Novotna, Vladimira;Veverka, Miroslav;Vejpravova, Jana;Hegmann, Torsten;Kohout, Michal. And the article was included in ACS Nano in 2022.Application of 2387-23-7 This article mentions the following:

Nanoparticles serving as a multifunctional and multiaddressable dopant to modify the properties of liquid crystalline matrixes are developed by combining cobalt ferrite nanocrystals with organic ligands featuring a robust photosensitive unit and a source of chirality from the natural pool. These nanoparticles provide a stable nanocomposite when dispersed in achiral liquid crystals, giving rise to chiral supramol. structures that can respond to UV-light illumination, and, at the same time, the formed nanocomposite possesses strong magnetic response. We report on a nanocomposite that shows three addnl. functionalities (chirality and responsiveness to UV light and magnetic field) upon the introduction of a single dopant into achiral liquid crystals. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Application of 2387-23-7).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Application of 2387-23-7

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

Reaction of electrogenerated cyanomethyl anion with cyclohexylisocyanate: synthesis of N-(cyclohexylcarbamoyl)acetamide. An unexpected product was written by Scarano, Vincenzo;Bortolami, Martina;Pandolfi, Fabiana;Petrucci, Rita;Rocco, Daniele;Zollo, Giuseppe;Feroci, Marta. And the article was included in Journal of the Electrochemical Society in 2020.Reference of 2387-23-7 This article mentions the following:

The contamination with H₂O of the cathodic ACN-Et₄NBF₄ solution gave the authors the opportunity to study alkyl isocyanate reactivity toward electrogenerated anions. The cathodic reduction of a ACN-Et₄NBF₄ solution gave both hydroxide and cyanomethyl anions. The reaction of the catholyte with cyclohexylisocyanate led to the exclusive formation of acetamidated product, with no traces of cyanomethylated one. On the contrary, when reacting with benzaldehyde only the cyanomethylated was isolated. Considering that the acetamidated product of benzaldehyde is reported to be unstable (thus its formation cannot be excluded), various experiments were carried out to understand the anomalous reactivity of cyclohexylisocyanate. Also, computational anal. allowed to state the higher stability of acetamidated product with respect to the cyanomethylated one. The possibility of a concerted reaction, instead of acetamide anion formation prior to the reaction, is still an open question. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Reference of 2387-23-7).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. In simple aromatic amides, fragmentation occurs on both sides of the carbonyl group. If a hydrogen is available in N-substituted aromatic amides, it tends to migrate and form an aromatic amine and the loss of a ketene.Reference of 2387-23-7

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

Photo-on-Demand Phosgenation Reactions with Chloroform for Selective Syntheses of N-Substituted Ureas and Isocyanates was written by Muranaka, Ryo;Liu, Yue;Okada, Itsuumi;Okazoe, Takashi;Tsuda, Akihiko. And the article was included in ACS Omega in 2022.Quality Control of 1,3-Dicyclohexylurea This article mentions the following:

Two new reaction processes involving the in situ oxidative photochem. conversion of CHCl₃ to COCl₂ allowed selective syntheses of N-substituted ureas and isocyanates from amines. (I) A CHCl₃ solution containing an amine and an organic base under O₂ bubbling provided the urea derivative under exposure to UV light generated from a low-pressure mercury lamp at 20-40°C. (II) A two-step reaction involving the oxidative photodecomposition of CHCl₃ at lower temperatures and subsequent sequential injections of an amine and organic base into the sample solution provided the isocyanate in high yield. The reaction processes of (I) and (II) capitalize on the solution conditions of [COCl₂] < [amine] and [COCl₂] > [amine], resp., to result in 1:2 and 1:1 reactions. In general, isocyanates, especially aromatic and haloalkyl ones, readily undergo hydrolysis in the presence of an organic base. However, with the advantage of synthesizing the isocyanates in CHCl₃ solvent, direct addition of monoalcs. and diols to the as-prepared sample solution containing the diisocyanate allowed the one-pot syntheses of biscarbamates and polyurethanes, resp. The reactions developed in this study are simple, safe, and inexpensive methods of synthesizing N-substituted ureas and isocyanates, and derivatives of isocyanates such as carbamates and polyurethanes. The present new methods can replace current synthetic methods using COCl₂ in both academia and industry. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Quality Control of 1,3-Dicyclohexylurea).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. The solubilities of amides and esters are roughly comparable. Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds. Tertiary amides, with the important exception of N,N-dimethylformamide, exhibit low solubility in water. Amides can be freed from solvent or water by drying below their melting points. These purifications can also be used for sulfonamides and acid hydrazides.Quality Control of 1,3-Dicyclohexylurea

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

Nonstrained γ-Butyrolactone to High-Molecular-Weight Poly(γ-butyrolactone): Facile Bulk Polymerization Using Economical Ureas/Alkoxides was written by Lin, Limiao;Han, Dongmei;Qin, Jiaxiang;Wang, Shuanjin;Xiao, Min;Sun, Luyi;Meng, Yuezhong. And the article was included in Macromolecules (Washington, DC, United States) in 2018.Recommanded Product: 1,3-Dicyclohexylurea This article mentions the following:

We disclose an efficient catalyst system of com. ureas/alkoxides for the challenging ring-opening polymerization (ROP) of bioderived “nonpolymerizable” γ-butyrolactone (γ-BL). This effective polymerization can not only be performed under mild conditions like bulk polymerization, higher monomer ratio, and elevated temperature (-20 °C comparing to -40 °C), but also obtains high-mol.-weight poly(γ-butyrolactone) (PγBL) (M_n up to 68.2 kg/mol). To our knowledge, this is a big progress in the research area of ROP of γ-BL, which provides a promising prospect for the industrial-scale methodol. of PγBL production Structural anal. including NMR and MALDI-TOF, along with mechanistic computational studies based on DFT calculations, show that urea anion acts as a bifunctional catalyst, which activates the alc. initiator and γ-BL before obeying an anionic polymerization Furthermore, the catalytic activities of ureas/alkoxides systems have been optimized using the ureas with electron-donating groups which are proved to have lower activation barrier by computational calculation In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Recommanded Product: 1,3-Dicyclohexylurea).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Amides can be viewed as a derivative of a carboxylic acid RC(=O)OH with the hydroxyl group –OH replaced by an amine group −NR′R″; or, equivalently, an acyl (alkanoyl) group RC(=O)− joined to an amine group. Ionic, or saltlike, amides are strongly alkaline compounds ordinarily made by treating ammonia, an amine, or a covalent amide with a reactive metal such as sodium.Recommanded Product: 1,3-Dicyclohexylurea

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

Reinforcement of hydrogen peroxide bleaching of bamboo pulp was written by Li, Peiyi;Zhang, Meiyun;Xia, Xinxing;Lin, Chuntao. And the article was included in Advanced Materials Research (Durnten-Zurich, Switzerland) in 2012.Application In Synthesis of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) This article mentions the following:

Magnesium-based alkalis and the Chelants (tetra acetyl ethylene diamine (TAED), Sodium Citrate and Opal) for hydrogen peroxide bleaching of bamboo pulp were investigated in this paper. The results showed that the optimal conditions of hydrogen peroxide bleaching of bamboo pulp were as follows: H₂O₂ 4%, Mg(OH)₂:NaOH=25%, Sodium Citrate 1%, Opal 1.5%, TAED:H₂O₂=0.67, temperature 60°C, and time 90 min. Under the optimum conditions, the brightness of bamboo pulp can be enhanced from 41.2% ISO to 78.2% ISO, while the brightness of bleached pulp by using the Mg(OH)₂-based alkalis was higher than by using NaOH as the alkali source. It can be seen that Sodium Citrate, Opal, and TAED activated H₂O₂ bleaching needed lower reaction temperature, shorter time, and got better brightness and alleviated environment pollution, compared with the conventional H₂O₂ bleaching of the same pulp. In the experiment, the researchers used many compounds, for example, N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4Application In Synthesis of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide)).

N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide) (cas: 10543-57-4) belongs to amides. Compared to amines, amides are very weak bases and do not have clearly defined acid–base properties in water. On the other hand, amides are much stronger bases than esters, aldehydes, and ketones. Amides are stable compounds. The lower-melting members (such as acetamide) can be readily purified by fractional distillation. Most amides are solids which have low solubilities in water.Application In Synthesis of N,N-(Ethane-1,2-diyl)bis(N-acetylacetamide)

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