Tag: M.W=50-100

Fan, Chunying published the artcileChemical compositions and copper(II) adsorption properties of sequentially extracted humic substances, including different humin fractions, Related Products of oxazolidine, the publication is Fresenius Environmental Bulletin (2018), 27(10), 6485-6499, database is CAplus.

Humin (HU) is the least understood humic substance (HS) fractions due to its close associations with soil mineral colloids. Here, humic acid (HA), fulvic acid (FA), HU, iron-bound HU (HUi), claybound HU (HUc) and residual HU (HUr) were sequentially extracted from an Alfisol of northeast China. Elemental anal., solid-state carbon-13 cross-polarization magic-angle-spinning NMR (13C CPMAS NMR) spectroscopy and pyrolysis-gas chromatog./mass spectrometry (Py-GC/MS) were used to characterize HS fractions. The adsorption isotherms of Cu(II) on HS fractions were obtained using batch equilibrium method. Among these HS fractions, HA contained higher proportion of phenols, whereas HUc exhibited higher proportion of aliphatic hydrocarbons. For the different HU fractions, n-alkanes/n-alkenes were particularly abundant in HUc, whereas polysaccharides were abundant in HUr. The adsorption of Cu(II) on HS fractions well fitted both Freundlich and Langmuir equations. The maximum amounts of Cu(II) adsorbed was FA > HUi > HA > HUc > HU > HUr, which was pos. correlated with their O/C ratio and carbonyl C whereas neg. correlated with C/N ratio (p < 0.01). The results suggested that HU is highly heterogeneous in terms of their chem. compositions and plays important role in controlling the behavior and fate of Cu(II) in the environment.

Fresenius Environmental Bulletin 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, Related Products of oxazolidine.

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

Adams, An published the artcileCharacterization of Model Melanoidins by the Thermal Degradation Profile, Computed Properties of 20662-83-3, the publication is Journal of Agricultural and Food Chemistry (2003), 51(15), 4338-4343, database is CAplus and MEDLINE.

Different types of model melanoidins (Maillard reaction products) were thermally degraded, with subsequent identification of the volatiles produced, to obtain and compare the thermal degradation profile of various melanoidins. At first, the volatiles produced from heated glucose/glycine standard melanoidins were compared with glucose/glutamic acid and L-(+)-ascorbic acid/glycine standard melanoidins. In the headspace of heated glucose/glycine melanoidins, mainly furans, were detected, accompanied by carbonyl compounds, pyrroles, pyrazines, pyridines, and some oxazoles. Heating of L-(+)-ascorbic acid/glycine melanoidins resulted in more N-heterocycles, while from glucose/glutamic acid melanoidins no N-heterocycles were formed. In a second part, a chem. treatment was applied to glucose/glycine melanoidins prior to the thermal degradation Acid hydrolysis was performed to cleave glycosidically linked sugar moieties from the melanoidin skeleton. Nonsol. glucose/glycine melanoidins were also subjected to an oxidation The results indicate that the thermal degradation profile is a useful tool in the characterization of different types of melanoidins.

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, Computed Properties of 20662-83-3.

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

Bredereck, Hellmut published the artcileFormamide reactions. I. Imidazole syntheses with formamide, SDS of cas: 20662-83-3, the publication is Chemische Berichte (1953), 88-96, database is CAplus.

α-HO, α-halo, α-NH₂, and, under reducing conditions, α-isonitroso ketones give 4,5-disubstituted imidazoles. Boiling 10 g. acetoin with 50 cc. HCONH₂ (I) 4 h. gives 55% 4,5-dimethylimidazole, HN.CH:N.CR:CR’ (II, R = R’ = Me) (III), b₁₁ 165-75°, m. 117° (HCl salt, m. 305°). Similarly, the following II (R = R’) are prepared (R, % yield, b.p., m.p., HCl salt (a) m.p. in the order given): Et, from propionoin, 67, b₁₀ 150-60°, 82-5°, a 252-3°; Pr, 81, b₁₀ 168°, 66°, a 163°; Bu, 72, b₁₁ 197-203°, -, a 147°; iso-Bu, 61, yellow oil, b. 177-9°, a (crystallizing with 1 H₂O) m. 72°, 131° (H₂O-free); Am, 51, light yellow oil, b₉ 210-16°, a 142°; C₆H₁₃, 45, -, -, a 130°; Me₂CH (IV), -, -, 214°, a 221° (formate salt, C₉H₁₆N₂.CH₂O₂ 85% yield, m. 140°; HBr salt, m. 225°). Refluxing 4 g. sebacoin with 15 cc. I 2 h. gives 87% 4,5-octamethyleneimidazole, needles, m. 229°, HCl salt m. 270°. 1-Cyclohexadecanol-2-one, b_0.03 156°, (8 g.) refluxed 2 h. with 50 cc. I gives 91% 4,5-tetradecamethyleneimidazole, leaflets, m. 115°, HCl salt m. 241°. 1,6-Diphenylpropionoin, b_0.05 180-90°, prepared in 53% yield from 29 g. PhCH₂CH₂CO₂Et and 8 g. Na in xylene, (5 g.) and 25 cc. I 2 h. give 66% II (R = R’ = PhCH₂CH₂), m. 112°. II are also prepared from benzoins, NH₂ ketones, and halogen ketones. Refluxing 10 g. benzoin with 20 cc. I 2 h. gives 91% II (R = R’ = Ph) (V), m. 231°; 10 g. furoin and 50 cc. I 2 h. give 89% II (R = R’ = α-furyl), m. 163°; p-dimethylaminobenzoin and I give 62% II [R = 4(5)-p-Me₂NC₆H₄, R’ = 5(4)-Ph], yellowish crystals, m. 230°; and 4 g. α-hydroxybutyrophenone and 20 cc. I 3 h. give 70% II (R = Ph, R’ = Et, or R and R’ may be interchanged), m. 172°. Refluxing 5 g. PhCOCHPhNH₂ 2 h. with 30 cc. I gives 90% V. Warming 10 g. benzilmonoxime with 70 cc. I and 3 cc. HCO₂H at 70° with slow addition of 2 g. NaHSO₃ and refluxing the mixture gently 1 h. give 71% V. Refluxing 8 g. PhCOCH₃Br and 50 cc. I 2 h. gives 90% II (R = Ph, R’ = H, or R and R’ may be interchanged), m. 128°; PhCOCHBrCHMe₂ and I give 69% II (R = Ph, R’ = Me₂CH, or R and R’ may be interchanged) b₁₅ 210-15°, m. 200°. PrCOCHBrEt and I 4 h. give 49% II (R = Et, R’ = Pr, or R and R’ may be interchanged), b₂₀ 185-95°; HCl salt m. 162°. Refluxing 25 g. MeCOCHBrMe and 100 cc. I 3 h. and fractionally distilling the product give 22% 4,5-dimethyloxazole, b₇₆₀ 129-35° [H₂PtCl₆ salt m. 240° (decomposition)], and 47% III, b₁₅ 170° (HBr salt, m. 265°). m-O₂NC₆H₄COCH₂Br and I 2 h. give 72% II (R = m-O₂NC₆H₄, R’ = H, or R and R’ may be interchanged), yellow crystals, m. 224°; p-MeO analog, 62%, leaflets, m. 137°.

Chemische Berichte 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

St. Angelo, A. J. published the artcileChemical and instrumental analyses of warmed-over flavor in beef, Application of 4,5-Dimethyloxazole, the publication is Journal of Food Science (1987), 52(5), 1163-8, database is CAplus.

Raw, freshly cooked, stored, and recooked beef muscle samples were assessed by chem., instrumental, and sensory methods of analyses for flavor quality, with particular emphasis on warmed-over flavor (WOF). The character notes used by a trained sensory panel to describe WOF were cardboardy, rancid, stale, and metallic. Samples analyzed by direct gas chromatog. utilizing either packed of fused silica capillary columns showed that compounds usually associated with lipid oxidation reactions could be used as marker compounds to follow the development of WOF. Of the many compounds that appeared to be markers, hexanal and 2,3-octanedione as well as total volatiles showed a highly significant degree of correlation when compared to sensory scores and 2-thiobarbituric acid (TBA) numbers Many of the volatile compounds that were identified in WOF meat samples were also found in the distillates prepared for the TBA reaction.

Journal of Food Science 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 C8H5F3N4, Application of 4,5-Dimethyloxazole.

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

Kulyk-Sindler, Marija published the artcileFormylation of 2,5-unsubstituted oxazoles: preparation and characterization of 2- and 5-formyl-4-methyloxazoles, SDS of cas: 20662-83-3, the publication is Heterocycles (1994), 38(8), 1791-6, database is CAplus.

Vilsmeier formylation of 4-methyloxazole gave a mixture of 4-methyl-5-oxazolecarboxaldehyde (2) and 4-methyl-2-oxazolecarboxaldehyde (3) in a 1:1 ratio. Both aldehydes were prepared unambiguously: aldehyde 2 by oxidation of 5-hydroxymethyl-4-methyloxazole and reduction of the chloride of 4-methyl-5-oxazolecarboxylic acid and aldehyde 3 by BuLi/DMF procedure. Aldehyde 2 sublimes in a refrigerator while aldehyde 3 forms hydrate, 5-dihydroxymethyl-4-methyloxazole.

Heterocycles 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

Pullman, Bernard published the artcileElectronic aspects of the mechanism of thiamine-catalyzed reactions, SDS of cas: 20662-83-3, the publication is Biochimica et Biophysica Acta (1961), 576-87, database is CAplus and MEDLINE.

cf. CA 54, 22747e. The method of mol. orbitals was used to calculate the energy levels and the electronic distribution in thiamine and related model compounds The results were used to interpret the mechanism of thiamine-catalyzed reactions, and were consistent with the hypothesis that the active center of the coenzyme is the highly charged C₂ atom of its thiazolium ring. 35 references.

Biochimica et Biophysica Acta 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

Dart, S. K. published the artcileThe changes in the volatile components of instant coffee with storage, Related Products of oxazolidine, the publication is Developments in Food Science (1985), 239-52, database is CAplus.

The headspace volatiles of fresh instant coffee were identified by capillary gas chromatog.-mass spectrometry, after enrichment on activated charcoal. The changes occurring to the volatiles during storage for â‰?2 mo at -18° and at ambient temperature were followed by direct headspace anal. Several components were highly susceptible to change, even at -18°. Overall, changes (increases as well as decreases) took place in about half the peaks, and these were interpreted in terms of the identifications made.

Developments in Food Science 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, Related Products of oxazolidine.

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

Jouquand, Celine published the artcileEffect of added nitrogen fertilizer on pyrazines of roasted chicory, Recommanded Product: 4,5-Dimethyloxazole, the publication is Journal of the Science of Food and Agriculture (2017), 97(4), 1172-1177, database is CAplus and MEDLINE.

BACKGROUND : Coffee substitutes made of roasted chicory are affected by the formation of acrylamide whose main precursor is asparagine. One strategy for limiting the formation of acrylamide is to reduce free asparagine in the chicory roots by lessening the supply of nitrogen in the field. However, decreasing nitrogen fertilizer could affect the formation of the volatile compounds and, consequently, the sensory characteristics of the roasted chicory. The present study aimed to investigate the impact of the nitrogen supply in five com. varieties on their aroma profile. RESULTS : The addition of 120 kg ha^-1 of nitrogen fertilizer in the field resulted in a greater amount of pyrazines in the roasted chicory. Triangle tests were performed to determine the effect of the nitrogen level on the sensory quality of the five varieties. The results revealed that the chicory aroma was modified in two out of five varieties. CONCLUSION : The results of the present study suggest that a strategy aiming to limit the amount of acrylamide could affect the sensory quality of some varieties of chicory. Further acceptance tests need to be conducted to assess the effect (whether favorable or otherwise) on the sensory quality of the coffee substitutes. © 2016 Society of Chem. Industry.

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, Recommanded Product: 4,5-Dimethyloxazole.

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

Nakamura, Shuichi published the artcileIdentification of volatile flavor components of the oil from roasted sesame seeds, Synthetic Route of 20662-83-3, the publication is Agricultural and Biological Chemistry (1989), 53(7), 1891-9, database is CAplus.

The volatile extract obtained by steam distillation of the oil from roasted sesame seeds was separated into its neutral, weakly acidic, acidic, and basic fractions. The neutral fraction was further separated by preparative TLC. All fractions were analyzed by a gas chromatograph (GC) equipped with FID and FPD, and by gas chromatog./mass spectrometry (GC/MS) and/or gas chromatog./Fourier transform-IR (GC/FT-IR) spectrometry. Two-hundred-and-twenty-one constituents were identified. One-hundred-and-forty-six of these compounds are being reported for the 1st time in the aroma of roasted sesame seeds, 7 of which were newly identified as naturally occurring flavor components. Two dithioketones, 1-methyldithio-2-propanone, and 1-methyldithio-2-butanone, are new compounds

Agricultural and Biological 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, Synthetic Route of 20662-83-3.

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

Trifonov, R. E. published the artcileBasicity of phenyl-substituted 1,3-oxazoles, Category: oxazolidine, the publication is Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii) (2001), 37(3), 416-420, database is CAplus.

Ph substituents in positions 2, 4, and 5 of the oxazole ring exert different effects on the electronic structure of the hetero ring, which are reflected in the basicity constants of isomeric phenyl-substituted oxazoles and in changes of the spectral patterns on protonation. The calculated (AM1) gas-phase proton affinities and energies of ionization of isomeric methyl-, phenyl-, and methylphenyloxazoles were correlated with the exptl. pK_BH⁺ values. In acid medium specific solvation of phenyloxazoles is possible with participation of the heterocyclic fragment.

Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii) 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 C8H19NO, Category: oxazolidine.

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