Month: November 2022

Mass Spectra of New Heterocycles: XXII. Electron Impact and Chemical Ionization of 1-Alkyl(cycloalkyl, alkoxyalkyl)-5-[(alkyl, allyl, benzyl)sulfanyl]-1H-pyrrol-2-amines was written by Klyba, L. V.;Nedolya, N. A.;Sanzheeva, E. R.;Tarasova, O. A.. And the article was included in Russian Journal of Organic Chemistry in 2021.Safety of Isopropylisothiocyanate The following contents are mentioned in the article:

Fragmentation of 1-alkyl(cycloalkyl, alkoxyalkyl)-5-[(alkyl, allyl, benzyl)sulfanyl]-1H-pyrrol-2-amines I [R¹ = Me, i-Pr, CH₂CH₂OMe, etc.; R² = R³ = Me, (CH₂)₄, (CH₂)₂O(CH₂)₂, etc.; R⁴ = Me, Et, allyl, Bn] under electron impact (70 eV) and chem. ionization (with methane as reactant gas) had been studied for first time. All examined compounds under electron impact generated mol. ion [M]^+· (I_rel 5-90%) whose primary fragmentation involved mainly cleavage of C-S bond in SR⁴ substituent with elimination of R⁴ radical (except for 1-isopropyl- and 1-cycloalkyl-1H-pyrrol-2-amines). The main pathway of decomposition of 1-isopropyl(cycloalkyl)-N,N-dimethyl-5-[(Me, allyl)sulfanyl]-1H-pyrrol-2-amines was cleavage of C-N bond with both elimination of R¹ radical from pyrrole nitrogen atom and fragmentation of pyrrole ring through elimination of imine (or aziridine) mol. and formation of odd-electron [M – NR¹]^+· radical cation. Chem. ionization of title compounds involved protonation, charge exchange, and electrophilic addition processes and elimination of Me (Et) and SMe (SEt) radicals from [M + H]⁺ ions. This study involved multiple reactions and reactants, such as Isopropylisothiocyanate (cas: 2253-73-8Safety of Isopropylisothiocyanate).

Isopropylisothiocyanate (cas: 2253-73-8) 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.Safety of Isopropylisothiocyanate

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

Headspace sampling-gas chromatograph-mass spectrometer as a screening method to thermally extract fireground contaminants from retired firefighting turnout jackets was written by Shinde, Adhiraj;Ormond, R. Bryan. And the article was included in Fire and Materials in 2021.Formula: C15H22O2 The following contents are mentioned in the article:

SUMMARY : Firefighters are at a 1.5 to 2 times greater risk of contracting certain types of cancers as compared to the general population. After preliminary studies, it was evident that contaminated turnout gear and ensemble elements could be linked to heightened cancer rates amongst firefighters. Compounds such as polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds, phenols, phthalates, brominated flame retardants, dioxins, volatile organic compounds, and many others are present in the contaminated gear, of which many are known carcinogens. A setup of headspace sampler-gas chromatograph-mass spectrometer was used to measure the off-gassing of the fabric samples taken from retired field-contaminated turnout jackets. The fabric samples were exposed to a specific temperature and allowed to equilibrate for a fixed time in the HS. A custom reference mix of phenols, phthalates and PAHs was put together to develop standard calibration curves. The compounds off-gassing from the outer shell, thermal liner and the moisture barrier were analyzed and the masses of certain marker compounds were calculated based of the standard calibration curves. The technique could be used as a screening method to thermally extract contaminants from field-contaminated firefighter turnout materials such as jackets, pants, gloves, and so on. This study involved multiple reactions and reactants, such as 2-Ethylhexyl benzoate (cas: 5444-75-7Formula: C15H22O2).

2-Ethylhexyl benzoate (cas: 5444-75-7) 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. 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.Formula: C15H22O2

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

Evaporative light scattering detection based reversed-phase ultra-high-performance liquid chromatography method to quantify intermediates and end products of biodiesel production was written by Nakai, Diogo K.;Ribeiro, Jose A. A.;Martins, Pedro A.;Soares, Itania P.;Salum, Thais F. C.;Costa, Patricia P. K. G.. And the article was included in Journal of Chromatography A in 2022.SDS of cas: 31566-31-1 The following contents are mentioned in the article:

A fast method based on reversed-phase ultra-high-performance liquid chromatog. using evaporative light scattering detection (RP-UHPLC-ELSD) was developed for monitoring the intermediates and end products of biodiesel production Gradient elution of water, acetonitrile, and a mixture of acetonitrile:2-propanol:n-hexane was used. With a minimal and easy sample preparation, fatty acid Me esters (FAME), fatty acid Et esters (FAEE), free fatty acids (FFA), monoacylglycerols (MAG), diacylglycerols (DAG), and triacylglycerols (TAG) were successfully separated The developed method was used to monitor an ethylic enzymic transesterification of soybean oil and to characterize the ester content of Me and Et biodiesel. The ester content obtained was compared with the reference method by gas chromatog. and flame ionization detector (GC-FID), with similar results for both Me and Et biodiesel. The presented method is a simple and fast alternative, a 17 min run, to monitor the transesterification process, simultaneously quantifying all the analytes produced in the reaction: biodiesel and its intermediates. Limits of detection (LOD, between 29 and 307 ng) and quantification (LOQ, between 48 and 614 ng), linearity (R2>0.99), precision (between 0.30 and 6.58%), and accuracy (between 81.6 and 119.9%) were determined for the twenty-one compounds This study involved multiple reactions and reactants, such as Glyceryl monostearate (cas: 31566-31-1SDS of cas: 31566-31-1).

Glyceryl monostearate (cas: 31566-31-1) 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. 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.SDS of cas: 31566-31-1

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

Proton affinities and ion enthalpies was written by Holmes, John L.;van Huizen, Nick A.;Burgers, Peter C.. And the article was included in European Journal of Mass Spectrometry in 2017.SDS of cas: 106-73-0 The following contents are mentioned in the article:

Proton affinities of a number of alkyl acetates (CH₃-C(=O)-OR) and of Me alkanoates (R-C(=O)-OCH₃, R=H, alkyl) have been assembled from the literature or measured using the kinetic method. It was observed that the proton affinities for the isomeric species CH₃-C(=O)-OR and R-C(=O)-OCH₃ are almost identical, an unexpected result as the charge in these protonated ester mols. is largely at the keto carbon atom and so this site should be more sensitive to alkyl substitution. Anal. of the data, including those from lone pair ionisation and core-electron ionisation experiments available from the literature, indicate that after protonation, extensive charge relaxation (or polarisation) takes place (as is also the case, according to the literature, after core-electron ionisation). By contrast, after lone pair ionisation, which results in radical cations, such relaxation processes are relatively less extensive. As a consequence, changes in ion enthalpies of these protonated mols. follow more closely the changes in neutral enthalpies, compared with changes in enthalpies of the corresponding radical cations, formed by electron detachment. Preliminary analyses of published energetic data indicate that the above finding for organic esters may well be another example of a more general phenomenon. This study involved multiple reactions and reactants, such as Methyl heptanoate (cas: 106-73-0SDS of cas: 106-73-0).

Methyl heptanoate (cas: 106-73-0) 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. 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.SDS of cas: 106-73-0

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

Influence of vinification process over the composition of volatile compounds and sensorial characteristics of greek wines was written by de Souza, Joao Carlos;Crupi, Pasquale;Colletta, Antonio;Antonacci, Donato;Toci, Aline Theodoro. And the article was included in Journal of Food Science and Technology in 2022.Safety of Isopentyl hexanoate The following contents are mentioned in the article:

Wine is one of the most traditional consumed alc. beverages in the world. Millions of wine enthusiasts worldwide duly appreciate a wine of excellent quality in terms of physicochem. and sensorial properties. Different classes of wines have different volatile compositions and sensorial properties, which can be altered, depending on the vinification process and use of additives. Among the widely employed additives in wine production is sulfite (SO2). The popularity of sulfite lies in its ability to preserve the flavor and freshness of wine; however, depending on the quantity, sulfite can pose serious health risks to consumers and affect the quality of the drink. The present study evaluated and compared the compositions of volatile compounds and sensorial properties of sparkling and traditional wines (with and without SO2) produced from Greek grapes Grechetto, Greco bianco and Greco di tufo. The results obtained of the composition of volatile compounds in these wines pointed to differences between SO2-containing, SO2-free and sparkling wines, with different amounts of compounds such as alcs., esters, fatty acids, phenols and differences in sensorial properties. The Grechetto wine, prepared without SO2, exhibited greater quality, better volatile composition, and better sensorial properties compared to the wines produced with SO2. This study involved multiple reactions and reactants, such as Isopentyl hexanoate (cas: 2198-61-0Safety of Isopentyl hexanoate).

Isopentyl hexanoate (cas: 2198-61-0) 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.Safety of Isopentyl hexanoate

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

Identification of anti-hepatic fibrosis components in Periplaneta americana based on spectrum-effect relationship and chemical component separation was written by Fu, Wenpeng;Zhao, Yanwen;Xie, Jingjing;Yang, Yongshou;Xiao, Peiyun. And the article was included in Biomedical Chromatography in 2022.HPLC of Formula: 1731-94-8 The following contents are mentioned in the article:

Periplaneta americana (PA) is used as a traditional medicine for hepatic diseases such as hepatic fibrosis in China. However, the relationship between the corresponding therapeutic effect and the chem. composition is still unclear. In this study, spectrum-effect relationship and chem. component separation were used to discover the potential of anti-hepatic fibrosis components of PA. The fingerprints of 10 batches of samples were established using HPLC, and the anti-hepatic fibrosis effect was determined using HSC-T6 cells. The spectrum-effect relationship between common peaks and efficacy values was established using partial least squares anal. Partial peaks in the fingerprints were identified, including X4 (9,12-heptadecanedenoic acid glyceride), X5 (nonadecanoic acid Me ester), X6 (glyceryl oleate), X7 (13,16,19-eicosatrienoic acid), X9 (linoleic acid), X10 (9,12,15-octadecatrienoic acid glyceride), X12 (hexadecanoic acid), X13 (oleic acid), and X14 (octadecanoic acid), and their anti-hepatic fibrosis activity was tested to verify the results of spectrum-effect relationships. The results showed that X4, X6, X7, and X10 were the active ingredients of PA. This work successfully identified the partial anti-hepatic fibrosis components of PA, which can be used to explain the material basis for the PA anti-hepatic fibrosis effect. This study involved multiple reactions and reactants, such as Methyl nonadecanoate (cas: 1731-94-8HPLC of Formula: 1731-94-8).

Methyl nonadecanoate (cas: 1731-94-8) 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. 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.HPLC of Formula: 1731-94-8

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

Synthesis of 9(E)-dodecenyl acetate and 9(E),11-dodecadienyl acetate, female sex pheromones of red bollworm moth, Diparopsis castanea Hmps was written by Vig, O. P.;Sharma, M. L.;Verma, N. K.;Malik, Neera. And the article was included in Indian Journal of Chemistry in 1980.Name: (E)-Dodeca-9,11-dien-1-yl acetate The following contents are mentioned in the article:

Undec-10-en-1-ol reacted with dihydropyran in the presence of a catalytic amount of concentrate HCl at 0° to give the pyranyl ether, which on epoxidation with m-chloroperbenzoic acid gave the epoxide I in very high yields. Cleavage of I with lithium diisopropylamide under N₂ atm. gave 11-(tetrahydropyranyloxy)undec-2(E)-en-1-ol (II), which on oxidation by pyridinium chlorochromate in dry CH₂Cl₂ gave 11-(tetrahydropyranyloxy)undec-2(E)-en-1-al (III). III on Wittig reaction with methylenetriphenylphosphorane in Me₂SO under N₂ gave the conjugated diene IV, which was cleaved to give 9(E),11-dodecadien-1-ol. This with isopropenyl acetate gave 9(E),11-dodecadienyl acetate. Conversion of the intermediate alc. II into the corresponding mesylate with MeSO₂Cl/Et₃N in dry CH₂Cl₂ at 0° and subsequent treatment with lithium dimethylcuprate under N₂ atm. gave 12-(tetrahydropyranyloxy)dodec-3(E)-ene. Removal of the protective pyranyl group from the latter gave 9(E)-dodecen-1-ol, which with Ac₂O/dry pyridine gave 9(E)-dodecenyl acetate. This study involved multiple reactions and reactants, such as (E)-Dodeca-9,11-dien-1-yl acetate (cas: 50767-78-7Name: (E)-Dodeca-9,11-dien-1-yl acetate).

(E)-Dodeca-9,11-dien-1-yl acetate (cas: 50767-78-7) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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.Name: (E)-Dodeca-9,11-dien-1-yl acetate

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

Mitigation of bromine-containing products during pyrolysis of polycarbonate-based tetrabromobisphenol A in the presence of copper(I) oxide was written by Oleszek, Sylwia;Kumagai, Shogo;Grabda, Mariusz;Shiota, Kenji;Yoshioka, Toshiaki;Takaoka, Masaki. And the article was included in Journal of Hazardous Materials in 2021.Application In Synthesis of Diphenyl carbonate The following contents are mentioned in the article:

Polycarbonate (PC) is an engineering thermoplastic that is widely used in elec. and electronic equipment. This plastic often contains tetrabromobisphenol A (TBBA), the most common brominated flame retardant. Thermal degradation of the PC-TBBA leads to generation of numerous bromo-organic products in the pyrolytic oil, hindering its appropriate utilization, as well as corrosive hydrogen bromide gas. The purpose of this study was to exptl. investigate and compare the pyrolysis products of PC-TBBA and PC-TBBA + Cu₂O at various temperatures, with an emphasis on the yield and distribution of brominated compounds In pyrolysis of PC-TBBA + Cu₂O, at the maximum degradation temperature (600 °C), as much as 86% of total Br was trapped in the residue, while 3% and 11% were distributed in the condensate and gas fractions, resp. In contrast, the distribution of Br from non-catalytic pyrolysis of PC-TBBA (600 °C) was 0.5% residue, 40% condensate, and 60% gas. The results of this study revealed that in the presence of Cu₂O, organo-bromine products were most likely involved in Ullman-type coupling reactions, leading to early crosslinking of the polymer network that efficiently hinders their vaporization. HBr in the gas fraction was suppressed due to effective fixation of bromine in residue in the form of CuBr. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Application In Synthesis of Diphenyl carbonate).

Diphenyl carbonate (cas: 102-09-0) 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. 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 In Synthesis of Diphenyl carbonate

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

Hybrid heat-integrated design and control for a diphenyl carbonate reactive distillation process was written by Lee, Hao-Yeh;Novita, Felicia Januarlia;Weng, Kuo-Chun. And the article was included in Chemical Engineering and Processing in 2021.Application of 102-09-0 The following contents are mentioned in the article:

This study proposed the design and control system of a hybrid heat-integrated configuration for the di-Ph carbonate (DPC) indirect reactive distillation (RD) process. First, an existing DPC production process with an RD column and a distillation column (C1) as the base case was modified and optimized for further evaluation. Both thermally coupled distillation (TCD) and double-effect (DE) configurations were examined to simultaneously improve the energy efficiency. A hybrid heat-integrated configuration for the DPC indirect RD process was finally proposed. The remixing effect at the top part of the RD column could be removed, and the energy wastage in the condenser of the C1 was lower than that in the TCD configuration. The heat exchanger (HE) area was smaller than that in the DE configuration. Among all configurations, the hybrid configuration was superior; around 34.0% of energy could be saved for producing 99.5 mol% of DPC. Then, three control structures (CS1, CS2, and CS3) and two inventory control loops (inventories A and B) were proposed in the hybrid heat-integrated configuration. Pressure-compensated temperature (PCT) control was also applied to eliminate the effect of pressure floating. The dynamic simulation results revealed that the CS3 PCT could maintain specifications during throughput and composition disturbances. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Application of 102-09-0).

Diphenyl carbonate (cas: 102-09-0) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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.Application of 102-09-0

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

Short-Chain Mono-Alkyl β-D-Glucoside Crystals-Do They Form a Cubic Crystal Structure? was written by Ogawa, Shigesaburo;Takahashi, Isao. And the article was included in Molecules in 2022.HPLC of Formula: 604-69-3 The following contents are mentioned in the article:

Three-dimensional liquid crystal (LC) phases, cubic LC phases, have been extensively studied as fascinating mol. assembled systems formed by amphiphilic compounds However, similar structures have only been seen in rare instances in lipid crystal states in glycolipid crystal studies. In this study, we prepared short-chain n-alkyl β-D-glucosides (CnG) with an alkyl chain length n ranging from 4 to 6 and investigated their crystal structures. First, DTA (DTA) and thermogravimetric anal. (TG) measurements showed the formation of hydrated crystals for C4G and C5G, resp. Second, the crystal structures of CnG (n = 4, 5, 6) in both anhydrous and hydrated states were examined using a temperature-controlled powder X-ray diffraction (PXRD) measurement. Both hydrate and anhydrous crystals of C4G and C5G with critical packing parameters (CPPs) less than 0.33 formed cubic crystal phases. Bilayer lengths, calculated from the main diffraction peaks in each PXRD profile, depended on crystalline moisture for C5G, but no significant change was confirmed for C4G, indicating that the properties of each hydrophilic layer differ. However, C6G with a CPP of 0.42 formed a crystal structure with a modulated lamellar structure similar to C7G and C8G with similar CPP values. Thus, a glycolipid motif concept with a cubic crystal structure was demonstrated. This study involved multiple reactions and reactants, such as (2S,3R,4S,5R,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 604-69-3HPLC of Formula: 604-69-3).

(2S,3R,4S,5R,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 604-69-3) 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 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.HPLC of Formula: 604-69-3

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