Tag: M.W=50-100

Mahadevan, Kritika published the artcileKey Odor Impact Compounds in Three Yeast Extract Pastes, Application In Synthesis of 20662-83-3, the publication is Journal of Agricultural and Food Chemistry (2006), 54(19), 7242-7250, database is CAplus and MEDLINE.

Three types of yeast extract pastes from 2 different suppliers were compared. Compounds responsible for the key odors include 2-methyl-3-furanthiol, 2-methyl-3-methyldithiofuran, methional, 1-octen-3-one, di-Me trisulfide together with a number of pyrazines, thiophenes, and aliphatic compounds The 3 types of yeast extract paste differed in the intensity of their main odors and, in particular, those caused by furans, furanthiols, and heterocyclic sulfur compounds Not only do pastes from different suppliers differ in terms of odor volatiles, but so do different treatments and batches of yeast extract from one supplier. The results suggest that normal variations in the concentrations of precursors and processing conditions may cause variations in the flavor of the end product.

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 In Synthesis of 20662-83-3.

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

Brown, Desmond J. published the artcileSpectra, ionization, and deuteration of oxazoles and related compounds, HPLC of Formula: 20662-83-3, the publication is Journal of the Chemical Society [Section] B: Physical Organic (1969), 270-6, database is CAplus.

The 1H N.M.R. spectra of oxazole, its derivatives and some related compounds in nonpolar, polar, and protonating media are discussed. The pKa values for oxazole (0.8, measured by the chem. shifts of H-2 in acidic media) and its derivatives show that the nucleus is far less basic than previously supposed, primarily owing to the powerful inductive effect of the O atom. The uv spectra of 2,5- and 2,4-diphenyloxazole indicate through-conjugation only in the former. This fact and other data suggest that oxazoles should be considered more as conjugated dienes than as fully aromatic compounds The rates for the 2-deuteration of simple oxazoles increase with the alkalinity; oxazole also undergoes 5- but not 4-deuteration under extreme conditions. On these grounds, the electron-distribution of the 3 C atoms of oxazole is clearly in the order 4 > 5 > 2. This is confirmed by the chem. shifts of the resp. protons and the pKa values of 2-, 4-, and 5-carboxyoxazole. Isoxazole (pKa – 2.03) is a much weaker base than previously reported.

Journal of the Chemical Society [Section] B: Physical Organic 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, HPLC of Formula: 20662-83-3.

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

Bredereck, H. published the artcileA new synthesis of β-oxocarboxylic acid amides and substituted quinolines, Recommanded Product: 4,5-Dimethyloxazole, the publication is Angewandte Chemie (1959), 32, database is CAplus.

Molar amounts of POCl₃ produce a self-condensation of N,N-dimethylcarboxamides to β-oxo-N,N-dimethylcarboxamides which then react with aromatic amines and POCl₃ to yield substituted 2-dimethylaminoquinolines. Thus, from acetic, propionic, and butyric acid dimethylamides are obtained the corresponding α-acyl-N,N-dimethylcarboxamides. The acetylacetic acid dimethylamide and aniline give a moderate yield of 2-dimethylamino-4-methylquinoline, obtained in better yield starting from β-dimethylaminocrotonic acid N,N-dimethylamide.

Angewandte Chemie 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

Bredereck, Hellmut published the artcileRing cleavage of oxazoles with 2,4-dinitrophenylhydrazine, Synthetic Route of 20662-83-3, the publication is Chemische Berichte (1960), 2010-15, database is CAplus.

The ring cleavage of oxazoles with 2,4-(O₂N)₂C₆H₃NHNH₂ (I) to the osazones of glyoxal derivatives is described. BzCHBrMe (63 g.), 96 g. HCO₂NH₄, 390 g. HOC₂H, and 45 cc. Ac₂O refluxed 5 hrs. and distilled gave 24 g. 5-methyl-4-phenyloxazole (II), b₁₁ 122°, m. 1°, n²⁰_D 1.5723. BzCH(OH)Ph (53 g.), 225 g. HCONH₂, and 49 g. concentrated H₂SO₄ heated 1 hr. at 100-20° and 2 hrs. at 150° yielded 33.5 g. 4,5-diphenyloxazole (IIa), b_0.002 115°, m. 44°. BzCH₂Br (100 g.) and 50 g. AcNH₂ heated 2 hrs. at 120-40° gave 35 g. 2-methyl-4-phenyloxazole (III), b₁₁ 116°, m. 42.5°. The appropriate oxazole (about 1 g.) in 10 cc. MeOH and 600 cc. reagent solution (cold-saturated solution of I in 2N HCl) kept at room temperature and filtered, and the residue washed with 2N HCl and H₂O, dried, and recrystallized from HCONMe₂ gave the corresponding cleavage product. III gave (during 2 weeks) phenylglyoxal 2,4-dinitrophenylosazone (IV), m. 299-300°, and benzoylcarbinol 2,4-dinitrophenylosazone (V), m. 234-5°. 4-Phenyloxazole (VI) gave (during 6 weeks) IV and V. 2-Methyl-4-carbethoxyoxazole (VII) gave (during 2 days) Et α-acetamido-α-formylacetate 2,4-dinitrophenylhydrazone (VIII), m. 185-6° (EtOAc), and (during 12 days) VIII and [2,4-(O₂N)₂C₆H₃NHN: CH]₂ (IX), m. 328-30°. The appropriate oxazole (about 1 g.) refluxed with 400 cc. reagent solution (1% I in 2N HCl) and worked up in the usual manner gave the derivative of the cleavage product(s) in 75-95% yield. IIa gave [2,4-(O₂N)₂C₆H₃NHN:CPh]₂, m. 310-11° (decomposition), which was also obtained by refluxing 2 g. Bz₂, 5 g. I, and 400 cc. 6N HCl 10 hrs., and boiling the precipitate with 300 cc. EtOAc and recrystallizing it from HCONMe₂. 4,5-Dimethyloxazole, b₇₆₀ 128°, n²⁰_D 1.4281, and 2,4,5-trimethyloxazole, b₁₁ 43°, n²⁰_D 1.4270, yielded similarly [2,4-(O₂N)₂C₆H₃NHN:-CMe]₂, m. 330-3° (decomposition). II, 5-methyl-4-phenyloxazole, and 2,5-dimethyl-4-phenyloxazole gave methylphenylglyoxal 2,4-dinitrophenylosazone, m. 259°. VII gave IX, m. 328-30° (decomposition). III and VI yielded IV, m. 299-300°. 5-Ethyl-4-phenyloxazole and 2-methyl-5-ethyl-4-phenyloxazole yielded ethylphenylglyoxal 2,4-dinitrophenylosazone, m. 226°. 5-Propyl-4-phenyloxazole gave propylphenylglyoxal 2,4-dinitrophenylosazone, m. 244°. 4-Methyl-5-benzyl-, 2,4-dimethyl-5-benzyl-, and 2,5-dimethyl-4-benzyloxazole yielded methylbenzylglyoxal 2,4-dinitrophenylosazone, m. 264°. 4,5-Diethyloxazole, 2-methyl-4,5-diethyloxazole, b₃₀ 76°, n²⁰_D 1.4423, and 2,4,5-triethyloxazole, b₃₀ 85°, n²⁰_D 1.4494, gave [2,4-(O₂N)₂C₆H₃NHN:CEt]₂, m. 290-1°.

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, Synthetic Route of 20662-83-3.

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

Hay, Duncan A. published the artcileA flexible synthesis of C-6 and N-1 analogues of a 4-amino-1,3-dihydroimidazo[4,5-c]pyridin-2-one core, Application In Synthesis of 20662-83-3, the publication is Tetrahedron Letters (2011), 52(44), 5728-5732, database is CAplus.

A flexible route which enables access to derivatives of 4-amino-1,3-dihydroimidazo[4,5-c]pyridin-2-ones is described. Issues of selectivity, reaction safety, and low yields in original routes are overcome with the key improvements to the route, including a Negishi cross-coupling and use of a carbamate as a protecting group and intrinsic carbonyl source. The new route enables variation of C-6 and N-1 substituents.

Tetrahedron Letters 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 In Synthesis of 20662-83-3.

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

Schwanz, Thiago G. published the artcileAnalysis of chemosensory markers in cigarette smoke from different tobacco varieties by GC×GC-TOFMS and chemometrics, Quality Control of 20662-83-3, the publication is Talanta (2019), 74-89, database is CAplus and MEDLINE.

Com. cigarettes are made from a blend of different tobacco varieties, which in turn are the results of different agronomic practices and post-harvest curing processes. The highly complex mixture of smoke compounds reflects each tobacco variety and the levels of sensory-relevant markers. Therefore, the aim of this work was to identify potential relevant chemosensory markers in the mainstream smoke of four main types of com. tobaccos and establish any possible relationship between them and the tobacco growing/curing practices. The tobacco samples were segregated into four segments: (1) three curing stages of flue-cured Virginia, (2) three curing stages of air-cured Burley, (3) three geo-regions of sun-cured Oriental and (4) three different process applied to tobacco. One hundred and twenty cigarettes (10 batches per flavor category) were produced and smoked under standard machine-smoking protocols. The mainstream smoke samples collected were extracted and analyzed by GC × GC TOFMS. The processed data was analyzed by partial least square discriminant anal. (PLS-DA) and the selectivity ratio was used to identify key chemosensory markers responsible for the four segments. All models had sensitivity and specificity equal to unity. Flue-cured Virginia (193 markers) and air-cured Burley (184 markers) showed a similar trend for O-heterocycles markers in the lighter leaf colors and N-heterocycles in the darker leaf colors post-processing, but they had compounds of different flavor descriptions, e. g. sweet and nutty. The three geo-regions of sun-cured Oriental (290 markers) also presented O-heterocycles markers in correlation with leaf sugar contents in addition of sucrose esters markers. The three unusually processed tobacco generated many chem. markers (436 markers), some derived from the so-called Cavendish fermentation process with sweet, spicy and peppery notes, whereas the dark fermented air-cured tobacco presented similar descriptors as air-cured Burley. In addition, some polycyclic aromatic hydrocarbons (PAH) were detected as markers from the fire-curing process. The PLS-DA with selectivity ratio evidenced total of 1098 chemosensory markers in cigarette smoke, in which 173 were tentatively identified.

Talanta 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 C11H10N4, Quality Control of 20662-83-3.

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

Baltes, Werner published the artcileModel reactions on roast aroma formation. V. Mass spectrometric identification of pyridines, oxazoles, and carbocyclic compounds from the reaction of serine and threonine with sucrose under the conditions of coffee roasting, Application of 4,5-Dimethyloxazole, the publication is Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung (1987), 185(1), 5-9, database is CAplus.

From the reaction of serine, threonine and sucrose under the conditions of coffee roasting, 33 pyridines, 20 oxazoles, and 12 carbocyclic compounds, among others, were identified in the volatile fraction. Their mass spectra and retention indexes are reported and the reaction products were compared with those formed by roasting coffee under the same conditions.

Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung 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

Solina, Marica published the artcileVolatile aroma components of soy protein isolate and acid-hydrolyzed vegetable protein, SDS of cas: 20662-83-3, the publication is Food Chemistry (2004), 90(4), 861-873, database is CAplus.

The volatile aroma components of soy protein isolate (SPI) and acid-hydrolyzed vegetable protein (aHVP) were compared by GC-MS and GC-olfactometry (GCO). Major differences were found between the 2 soy-based products. Aliphatic aldehydes and ketones were mainly found in SPI, whereas pyrazines and sulfur-containing compounds were dominant in aHVP. Analyses of the non-volatile components showed that SPI was mainly protein (82.5%) with some lipid (3.5%), whereas aHVP contained no protein, only free amino acids (18.4%) and a trace quantity of lipid (0.4%). Polyunsaturates (47.8%), followed by saturates (24.9%) and monounsaturates (14.8%) dominated the fatty acid profile of the SPI lipid fraction. Both SPI and aHVP had a free fatty acid content <0.1%. Sensory analyses of aqueous suspensions of SPI and aHVP demonstrated significant differences in the odors of the 2 products. Compounds responsible for some of these differences were identified by GCO and GC-MS analyses of aqueous suspensions. The possible role of SPI and aHVP in the development of aroma in extrudates containing these soy products is discussed.

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 C4H6N2, SDS of cas: 20662-83-3.

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

Viegas, Marcelo Caldeira published the artcileUse of the linear retention index for characterization of volatile compounds in soluble coffee using GC-MS and an HP-innowax column, Safety of 4,5-Dimethyloxazole, the publication is Quimica Nova (2007), 30(8), 2031-2034, database is CAplus.

Due to the complexity of the soluble coffee matrix, complete identification of flavor components should not be based on GC-MS anal. only. The linear retention index (LRI) is frequently used to give support to mass spectral data. Volatile compounds in dry lyophilized soluble Arabic coffee samples were characterized by head-space (solid-phase microextraction) GC-MS; the LRI values were determined with the HP-Innowax column. The combined method significantly increased the reliability of identifying the volatile compounds; 88 volatile compounds were identified.

Quimica Nova 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 C2H2N4O2, Safety of 4,5-Dimethyloxazole.

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

Piloty, Markus published the artcileInvestigations on the reaction of amino acids with α-dicarbonyl compounds. II. Volatile products of the reaction of amino acids with diacetyl (2,3-butanedione), COA of Formula: C5H7NO, the publication is Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung (1979), 168(5), 374-80, database is CAplus.

Glycine [56-40-6], α-alanine [56-41-7], β-alanine [107-95-9], phenylalanine [63-91-2], glycylalanine [3695-73-6], and NH₃ were reacted with diacetyl [431-03-8], in an aqueous medium. In addition to several N-free compounds, some nitrogenous heterocyclic products belonging to the classes oxazoles, pyrazines, pyrroles, and pyridines were identified. The pyridine derivatives have not previously been described in the literature. Spectral data are given and possible mechanisms of formation discussed in relation to food aroma.

Zeitschrift fuer Lebensmittel-Untersuchung und -Forschung 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, COA of Formula: C5H7NO.

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