Heterocyclic Building Blocks-Oxazolidine

Lu, Chih-ying published the artcileEffects of water content on volatile generation and peptide degradation in the Maillard reaction of glycine, diglycine, and triglycine, Safety of 4,5-Dimethyloxazole, the publication is Journal of Agricultural and Food Chemistry (2005), 53(16), 6443-6447, database is CAplus and MEDLINE.

Peptides abundant in food and protein hydrolyzates are known to be important to process flavors. The present study reports the volatile profile of the Maillard reactions of glycine, diglycine, and triglycine. The reaction with glucose was conducted at 0-100% water content in glycerol medium at 160° for 1 h. Volatile compounds were quantified by stir bar sorptive extraction-gas chromatog.-mass spectrometry, and nonvolatile compounds were quantified by high-performance liquid chromatog.-tandem mass spectrometry. The major volatiles produced from each of the reaction systems were trimethylpyrazine and 2,5-dimethylpyrazine. Volatile generation increased as water decreased, and the overall reactivity of the glycine and glycine peptides in volatile formation was glycine â‰?triglycine > diglycine. Triglycine was very unstable and mainly degraded into cyclic Gly-Gly and glycine, whereas diglycine had a higher stability than triglycine toward hydrolytic cleavage of the peptide bond. The amounts of glycine, diglycine, cyclic (Gly-Gly), and triglycine in the peptide-glucose reaction mixtures at different water content were reported.

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, Safety of 4,5-Dimethyloxazole.

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

Yaylayan, Varoujan A. published the artcileMechanism of imidazole and oxazole formation in [¹³C-2]-labelled glycine and alanine model systems, Category: oxazolidine, the publication is Food Chemistry (2003), 81(3), 403-409, database is CAplus.

Studies with ¹³C-2-labeled glycine and alanine in model systems containing 2,3-butanedione, glyceraldehyde or glyoxal have indicated that imidazoles and oxazoles can be formed from α-dicarbonyl compounds through Strecker reaction and subsequent formation of α-amino carbonyl reactive intermediates. These intermediates can react with any aldehyde in the reaction mixture to form an imine which in turn can either cyclize to form oxazoles or react with an amino compound and then cyclize to form imidazole after an oxidation step. On the other hand, Amadori products, formed in α-hydroxycarbonyl containing systems, can undergo decarboxylation followed by reaction with ammonia to form an amino imine intermediate which, after reaction with any aldehyde followed by cyclization, can form imidazoles after a dehydration step. This latter mechanism fixes the C-2 atom of glycine as an N-alkyl substituent in imidazoles. In addition, model studies with α-dicarbonyl compounds, using ammonium carbonate as a source of ammonia and paraformaldehyde as a source of formaldehyde, also produced imidazoles and oxazoles.

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 C5H8N2O, Category: oxazolidine.

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

Ames, Jennifer M. published the artcileEffect of pH and Temperature on the Formation of Volatile Compounds in Cysteine/Reducing Sugar/Starch Mixtures during Extrusion Cooking, HPLC of Formula: 20662-83-3, the publication is Journal of Agricultural and Food Chemistry (2001), 49(4), 1885-1894, database is CAplus and MEDLINE.

Mixtures of cysteine, reducing sugar (xylose or glucose), and starch were extrusion cooked using feed pH values of 5.5, 6.5, and 7.5 and target die temperatures of 120, 150, and 180 °C. Volatile compounds were isolated by headspace trapping onto Tenax and analyzed by gas chromatog.-mass spectrometry. Eighty and 38 compounds, resp., were identified from extrudates prepared using glucose and xylose. Amounts of most compounds increased with temperature and pH. Aliphatic sulfur compounds, thiophenes, pyrazines, and thiazoles were the most abundant chem. classes for the glucose samples, whereas for xylose extrudates highest levels were obtained for non-sulfur-containing furans, thiophenes, sulfur-containing furans, and pyrazines. 2-Furanmethanethiol and 2-methyl-3-furanthiol were present in extrudates prepared using both sugars, but levels were higher in xylose samples. The profiles of reaction products were different from those obtained from aqueous or reduced-moisture systems based on cysteine and either glucose or ribose.

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, HPLC of Formula: 20662-83-3.

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

Ames, Jennifer M. published the artcileEffect of pH, Temperature, and Moisture on the Formation of Volatile Compounds in Glycine/Glucose Model Systems, Category: oxazolidine, the publication is Journal of Agricultural and Food Chemistry (2001), 49(9), 4315-4323, database is CAplus and MEDLINE.

Mixtures of glycine, glucose, and starch were extrusion cooked using sodium hydroxide at 0, 3, and 6 g/L of extruder water feed, 18% moisture, and 120, 150, and 180 °C target die temperatures, giving extrudates with pH values of 5.6, 6.8, and 7.4. Freeze-dried equimolar solutions of glucose and glycine were heated either dry or after equilibration to �3% moisture at 180°C in a reaction-tube system designed to mimic the heating profile in an extruder. Volatile compounds were isolated onto Tenax and analyzed by gas chromatog.-mass spectrometry. For the extrudates, total yields of volatiles increased with decreasing pH at 180°C, reached a maximum at pH 6.8 at 150°C, and increased with increasing pH at 120°C. Amounts increased with temperature at all pH values. Pyrazines were the most abundant class for all sets of conditions (54-79% of total volatiles). Pyrroles, ketones, furans, oxazoles, and pyridines were also identified. Yields of volatiles from the reaction-tube samples increased by >60% in the moist system. Levels of individual classes also increased in the presence of moisture, except pyrazines, which decreased �.5-fold. Twenty-one of the compounds were common to the reaction-tube samples and the extrudates.

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, Category: oxazolidine.

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

Huang, Quan published the artcileTuning the dual emission of keto/enol forms of excited-state intramolecular proton transfer (ESIPT) emitters via intramolecular charge transfer (ICT), COA of Formula: C9H6BrNO, the publication is Dyes and Pigments (2021), 109497, database is CAplus.

Herein disclosed the adjustment of the dual emission of keto and enol forms of excited-state intramol. proton transfer (ESIPT) emitters via intramol. charge transfer (ICT) effects. Introducing electron-donating triphenylamine (TPA) and electron-withdrawing triphenylboron (TPB) substituents into the para-position of the phenolic hydroxyl group or the side of the oxazole of 2-(2′-hydroxyphenyl)oxazole skeleton endows the resulting compounds (6a-6d) with different photophys. properties. Owing to the ICT effect from electronic donor to acceptor, introducing TPA into the side of oxazole and TPB into the para-position of phenolic hydroxyl is conducive to an enol-form emission (6a). Exchanging the 2 substituents, introducing TPB into the side of oxazole and TPA into the para-position of phenolic hydroxyl, would be beneficial to a keto-form emission (6b). Synchronously introducing 2 identical substituents, whether TPA or TPB, into 2 sides of 2-(2′-hydroxyphenyl)oxazole skeleton (6c and 6d) would lead to the dual emission of keto and enol forms due to the excited-state equilibrium of ESIPT reactions, which are further verified by DFT calculation The organic light-emitting diode (OLED) devices with 6a and 6c as emitters were fabricated, both of which exhibit hybridized local and charge transfer (HLCT) excited-state characters with high external quantum efficiencies (EQEs) of 4.9% and 5.6%, resp.

Dyes and Pigments 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, COA of Formula: C9H6BrNO.

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

Murugesan, Natesan published the artcileBiphenylsulfonamide endothelin receptor antagonists: discovery of 4′-oxazolyl biphenylsulfonamides as a new class of potent, highly selective ET_A antagonists, Computed Properties of 72571-06-3, the publication is Journal of Medicinal Chemistry (2000), 43(16), 3111-3117, database is CAplus and MEDLINE.

The synthesis and structure-activity relationship (SAR) studies of a series of 4′-oxazolyl-N-(3,4-dimethyl-5-isoxazolyl)[1,1′-biphenyl]-2-sulfonamide derivatives as endothelin-A (ET_A) receptor antagonists are described. The data reveal a remarkable improvement in potency and metabolic stability when the 4′-position of the biphenylsulfonamide is substituted with an oxazole ring. Addnl. 2′-substitution of an acylaminomethyl group further increased the binding activity and provided one of the first subnanomolar ET_A-selective antagonists in the biphenylsulfonamide series (ET_A K_i = 0.2 nM). Among the compounds described, (N-(3,4-dimethyl-5-isoxazolyl)-4′-(2-oxazolyl)[1,1′-biphenyl]-2-sulfonamide; BMS-193884) had the optimum pharmacol. profile and was therefore selected as a clin. candidate for studies in congestive heart failure.

Journal of Medicinal Chemistry 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, Computed Properties of 72571-06-3.

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

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

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

Wen, Shu′an published the artcileComparison of the in vitro activity of linezolid, tedizolid, sutezolid, and delpazolid against rapidly growing mycobacteria isolated in Beijing, China, Computed Properties of 1219707-39-7, the publication is International Journal of Infectious Diseases (2021), 253-260, database is CAplus and MEDLINE.

The natural resistance of rapidly growing mycobacteria (RGM) to multiple antibiotics renders the treatment of the infections caused less successful. The objective of this study was to evaluate the in vitro susceptibilities of four oxazolidinones against different RGM species. The microplate alamarBlue assay was performed to identify the min. inhibitory concentrations (MICs) of four oxazolidinones as delpazolid, sutezolid, tedizolid, and linezolid for 32 reference strains and 115 clin. strains of different RGM species. The MIC breakpoint concentration was defined as 16 μg/mL for linezolid. Next, the gene fragments associated with oxazolidinone resistance were amplified and sequenced, and mutations were defined in contrast with the sequences of the reference strains. Tedizolid showed the strongest inhibitory activity against the Mycobacterium abscessus isolates. Delpazolid exhibited better antimicrobial activity against the Mycobacterium fortuitum isolates when compared to linezolid, with 4-fold lower MIC values. The protein alignment and structure-based anal. showed that there might be no correlation between oxazolidinone resistance and mutations in the rplC, rplD, and 23S rRNA genes in the tested RGM. Tedizolid had the strongest inhibitory activity against M. abscessus in vitro, while delpazolid presented the best inhibitory activity against M. fortuitum. This provides important insights into the potential clin. application of oxazolidinones to treat RGM infections.

International Journal of Infectious Diseases published new progress about 1219707-39-7. 1219707-39-7 belongs to oxazolidine, auxiliary class Other Aliphatic Heterocyclic,Oxazolidine,Chiral,Fluoride,Benzene,Amide,Alcohol,Anti-infection, name is (R)-3-(3-Fluoro-4-(1-methyl-5,6-dihydro-1,2,4-triazin-4(1H)-yl)phenyl)-5-(hydroxymethyl)oxazolidin-2-one, and the molecular formula is C8H14O4, Computed Properties of 1219707-39-7.

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