Day: November 21, 2022

Nishimura, O. published the artcileIdentification of volatile flavor components of the oil from roasted sesame seeds, Application of 4,5-Dimethyloxazole, the publication is Koryo (1990), 91-101, database is CAplus.

Two hundred and twenty-one constituents were identified from the volatile extract obtained by steam distillation of the oil from roasted sesame seeds. One hundred and forty-six of these compounds are reported for the first time in the aroma of roasted sesame seed, 7 of which were newly identified as naturally occurring flavor components. Two dithioketones, 1-methyl-2-propanone and 1-methyldithio-2-butanone, are new compounds

Koryo published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Application of 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Medvedskaya, L. B. published the artcileStructural orientation of heterodiene synthesis during the reaction of oxazoles with acetylenic dienophiles, Name: 4,5-Dimethyloxazole, the publication is Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya (1973), 1311-15, database is CAplus.

The Hueckel approximation of MO calculation gave the energy level values and electron densities in oxazoles with H, Me, Ac, CO2R and OR in the 5-position and Me in the 4-position. The stabilization energies of probable transition states in reactions of these compounds with acetylenic dienophiles (Et propiolate or Et phenylpropiolate) were computed. The results of these calculations agreed with the general results of Diels-Alder reactions of these substances. The π-electron density in the reactants was not a satisfactory criterion for deducing the orientation of such reactions since dynamic features were important. Hence, stabilization energy or some index of reactivity that describes reactant polarizability was the more useful parameter.

Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Name: 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Sanz, Cristina published the artcileProfiles of volatile compounds and sensory analysis of three blends of coffee: influence of different proportions of Arabica and Robusta and influence of roasting coffee with sugar, SDS of cas: 20662-83-3, the publication is Journal of the Science of Food and Agriculture (2002), 82(8), 840-847, database is CAplus.

One hundred and forty-six volatile compounds were identified and quantified using a static headspace sampler in 3 blends of coffee: Arabica/Robusta 80:20 (A80:R20) natural roasted coffee, Arabica/Robusta 20:80 (A20:R80) natural roasted coffee and Arabica/Robusta 20:80 with 50% of Robusta coffee roasted with sugar (A20:R80 50% Torrefacto). The different proportion of Arabica and Robusta coffee in the blend A80:R20 vs. A20:R80 influenced the amounts of 20 chem. families of volatile compounds Aldehydes, ketones, alcs., pyrroles, pyrazines, furans, thiazoles, thiophenes, esters, oxazoles, lactones, sulfur compounds, pyridines, alkanes, alkenes, phenolic compounds, benzenic compounds, acids, pyranones and terpenes were present in higher quantities in the sample containing 80% of Arabica coffee, whereas sulfur compounds were more abundant in the coffee with 80% of Robusta. Sensory differences were also found between the 2 blends of coffee in the burnt, caramel, nutty, earthy and roasty notes. Torrefacto coffee, widely consumed in Spain, is obtained by roasting coffee with sugar. Higher quantities of ketones, alcs., pyrazines, furans, pyridines, alkanes, phenolic compounds, pyranones and terpenes were found in the blend A20:R80 50% Torrefacto coffee vs. A20:R80 natural roasted coffee. These differences in the volatile fraction were perceived by our panelists in the intensities of the nutty, roasty, earthy, burnt and caramel notes.

Journal of the Science of Food and Agriculture published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, SDS of cas: 20662-83-3.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Mukku, Narasimharao published the artcileA Facile Microwave-Assisted Synthesis of Oxazoles and Diastereoselective Oxazolines Using Aryl-Aldehydes, p-Toluenesulfonylmethyl Isocyanide under Controlled Basic Conditions, SDS of cas: 72571-06-3, the publication is ACS Omega (2020), 5(43), 28239-28248, database is CAplus and MEDLINE.

In this study, a highly efficient two-component [3+2] cycloaddition reaction of substituted aryl aldehydes with 4-toluenesulfonylmethyl isocyanide (TosMIC) in the presence of 2 equiv of potassium phosphate as a base to 5-substituted oxazoles were established in a isopropanol medium under microwave irradiation However, using 1 equiv of K₃PO₄ as a base resulted in the diastereoselective synthesis of 4,5-disubstituted oxazolines under identical reaction conditions. The foremost benefits of these protocols are the moderate-to-excellent yields with good functional group compatibility, simple exptl. procedure, inexpensive readily available starting materials, nonchromatog. purification, and high bond-forming efficiency. The synthetic manipulation reported herein represents a cleaner route to the sustainable preparation of 5-substituted oxazoles and diastereoselective 4,5-disubstituted oxazolines derivatives

ACS Omega published new progress about 72571-06-3. 72571-06-3 belongs to oxazolidine, auxiliary class Oxazole,Bromide,Benzene, name is 5-(4-Bromophenyl)oxazole, and the molecular formula is C9H6BrNO, SDS of cas: 72571-06-3.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Eiserich, Jason P. published the artcileVolatile antioxidants formed from an L-cysteine/D-glucose Maillard model system, Application of 4,5-Dimethyloxazole, the publication is Journal of Agricultural and Food Chemistry (1992), 40(10), 1982-8, database is CAplus.

The microwave-induced volatile compounds formed from an L-cysteine/D-glucose Maillard model system at different pH values were evaluated for antioxidative activity using a newly developed method. The dichloromethane extracts of pH 9 and 5 showed the strongest antioxidative effects. Fractionation of the pH 9 extract by column chromatog. revealed three fractions possessing antioxidative activity. 2,4,5-Trimethyloxazole, 2,4,5-trimethylthiazole, 4,5-dimethylthiazole, oxazole, thiazole, and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) were identified in these fractions as volatile antioxidants. The strongest antioxidative activity was displayed by DMHF, followed by the oxazoles, whereas the thiazoles showed only slight activity. Trimethylpyrazine, another major volatile compound produced in the Maillard reaction, did not show any antioxidative activity. The antioxidative activities of these heterocyclic volatiles were directly dependent upon their concentrations

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Application of 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Hoff, Signe published the artcileQuality of pilsner malt and roasted malt during storage, Recommanded Product: 4,5-Dimethyloxazole, the publication is Journal of the Institute of Brewing (2014), 120(4), 331-340, database is CAplus.

Malt is usually expected to be stable during 12 mo of storage. However, in practice many brewers notice changes in malt aroma during storage. The oxidative stabilities of pilsner malt and roasted malt were evaluated during a 12 mo storage at different temperatures (10 and 20 °C) and water activities (0.231 and 0.432). The radical content in malt kernels was measured by ESR spectroscopy and the volatile profile of the resulting sweet worts was measured by head-space anal. followed by GC-MS anal. The storage of malt resulted in oxidative reactions and a large change of the volatile profile of the resulting worts. Roasted malt was much more unstable than pilsner malt, as illustrated by a higher initial radical intensity, larger radical decay during storage and a larger change in the volatile profile of the wort with increased amounts of lipid oxidation products. For both roasted malt and pilsner malt, good correlations were found between radical decay and changes in the volatile profile of the wort, where high temperature and high water activity resulted in the largest changes. During the 12 mo of storage, the sugar extract of the wort made from the malts remained constant and was not affected by the chem. changes. This study suggests that chem. changes occurring in malts during less than 12 mo of storage may potentially affect the aroma of beer, and that water activity and storage temperature should both be kept low in order to maintain a high malt quality. Copyright © 2014 The Institute of Brewing & Distilling

Journal of the Institute of Brewing published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Recommanded Product: 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Cheng, Xiaokai published the artcileEnantioselective benzylic C-H arylation via photoredox and nickel dual catalysis, Formula: C14H24N2O2, the publication is Nature Communications (2019), 10(1), 1-7, database is CAplus and MEDLINE.

Here, an enantioselective benzylic C(sp³)-H bond arylation via photoredox/nickel dual catalysis was reported. Sterically hindered chiral biimidazoline ligands were designed for this asym. cross-coupling reaction. Readily available alkyl benzenes and aryl bromides with various functional groups tolerance could be easily and directly transferred to useful chiral 1,1-diaryl alkanes I [R = Me, Et, Bn, etc.; Ar¹ = Ph, 4-MeOC₆H₄, 4-FC₆H₄, 4-iBuC₆H₄, 2-naphthyl; Ar² = 4-FC₆H₄, 3-CNC₆H₄, benzofuran-5-yl, etc.] including pharmaceutical intermediates and bioactive mols. This reaction proceeded smoothly under mild conditions without the use of external redox reagents.

Nature Communications published new progress about 138429-17-1. 138429-17-1 belongs to oxazolidine, auxiliary class BOX Ligands, name is (4S,4’S)-4,4′-Diisobutyl-4,4′,5,5′-tetrahydro-2,2′-bioxazole, and the molecular formula is C14H24N2O2, Formula: C14H24N2O2.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Terent’ev, P. B. published the artcileReaction of vinylpyridines with oxazoles, COA of Formula: C5H7NO, the publication is Khimiya Geterotsiklicheskikh Soedinenii (1980), 1255-62, database is CAplus.

The regioselectivity observed in the cycloaddition reactions of vinylpyridines with oxazoles was predicted by MO calculation of HOMO and LUMO energies and product stabilization energies. Thus, 2-vinylpyridine reacted with 2,4-dimethyloxazole (I) to give II; III reacted with I to give IV. The structure of the bicyclic products was determined by oxidation to bipyridines and spectral anal. of the latter.

Khimiya Geterotsiklicheskikh Soedinenii published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C11H24O3, COA of Formula: C5H7NO.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Zhou, Zhilei published the artcileElucidation of the aroma compositions of Zhenjiang aromatic vinegar using comprehensive two dimensional gas chromatography coupled to time-of-flight mass spectrometry and gas chromatography-olfactometry, Computed Properties of 20662-83-3, the publication is Journal of Chromatography A (2017), 218-226, database is CAplus and MEDLINE.

In this work, a method to characterize the aroma compounds of Zhenjiang aromatic vinegar (ZAV) was developed using comprehensive two dimensional gas chromatog. (GC × GC) coupled with time-of-flight mass spectrometry (TOFMS) and gas chromatog. olfactometry (GC-O). The column combination was optimized and good separation was achieved. Structured chromatograms of furans and pyrazines were obtained and discussed. A total of 360 compounds were tentatively identified based on mass spectrum match factors, structured chromatogram and linear retention indexes comparison. The most abundant class in number was ketones. A large number of esters, furans and derivatives, aldehydes and alcs. were also detected. The odor-active components were identified by comparison of the reported odor of the identified compounds with the odor of corresponding GC-O region. The odorants of methanethiol, 2-methyl-propanal, 2-methyl-butanal/3-methyl-butanal, octanal, 1-octen-3-one, di-Me trisulfide, trimethyl-pyrazine, acetic acid, 3-(methylthio)-propanal, furfural, benzeneacetaldehyde, 3-methyl-butanoic acid/2-methyl-butanoic acid and phenethyl acetate were suspected to be the most potent. About half of them were identified as significant aroma constituents in ZAV for the first time. Their contribution to specific sensory attribute of ZAJ was also studied. The results indicated that the presented method is suitable for characterization of ZAV aroma constituents. This study also enriches our knowledge on the components and aroma of ZAV.

Journal of Chromatography A published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C6H6N2O, Computed Properties of 20662-83-3.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

van Loon, Wil A. M. published the artcileIdentification and olfactometry of French fries flavor extracted at mouth conditions, Formula: C5H7NO, the publication is Food Chemistry (2004), 90(3), 417-425, database is CAplus.

The aim of this study was to isolate and identify odor active compounds from French fries at mouth conditions. Volatile compounds were released from French fries by purge-and-trap, trapped on Tenax TA, and identified with GC-MS. GC-olfactometry was used to determine odor active compounds with a trained panel using the detection frequency method. A total of 122 compounds were identified of which 85% originated from either sugar degradation and/or Maillard reaction and 15% from lipid degradation, based on relative areas. About 50 odor active compounds were, due to co-elution, responsible for 41 odors perceived by the panel. 3-Methylbutanal and 2-methylbutanal, hexanal, 2,3-dimethylpyrazine, 2-methylpropanal, 2,3-butanedione, pyridine, heptanal, 2,5-dimethylpyrazine and/or 2,6-dimethylpyrazine and/or ethylpyrazine, di-Me trisulfide, octanal, phenylacetaldehyde, 2,5-diethylpyrazine, (E)-2-nonenal, 3-methylbutanoic acid and/or 2-methylbutanoic acid, (E,Z)-2,4-heptadienal, (E)-2-octenal, 5-ethyl-2,3-dimethylpyrazine and/or 2-ethyl- 3,5-dimethylpyrazine, nonanal, and tentatively 2-methylpyrrole had the highest detection frequencies. This resulted in a strong malty and fried potato note, combined with caramel/buttery, green, spicy, and deep-fried notes. Also chem. and sweaty odors were observed

Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C13H14N2O, Formula: C5H7NO.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem