Day: December 21, 2022

Roy, Patrick J. published the artcileThe Hemetsberger-Knittel synthesis of substituted 5-, 6-, and 7-azaindoles, HPLC of Formula: 71255-09-9, the main research area is pyrrolo pyridine azaindole preparation cyclization thermolysis pyridinyl azido propenoate; azido pyridine acrylate preparation thermal cyclization Hemetsberger Knittel; Hemetsberger Knittel synthesis azaindole thermolysis cyclization template.

A series of substituted 5-, 6-, and 7-azaindoles were prepared via the Hemetsberger-Knittel reaction. In general, better yields were obtained at higher temperatures and shorter reaction times than required for the formation of the analogous indoles, and in some cases, only decomposition occurred below a min. temperature The resulting templates offer up to five sites for subsequent functionalization to allow a wide range of chem. diversity.

Synthesis published new progress about Cyclization. 71255-09-9 belongs to class pyridine-derivatives, name is 2-Methoxynicotinaldehyde, and the molecular formula is C7H7NO2, HPLC of Formula: 71255-09-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Trecourt, Francois published the artcileSynthesis of diazaxanthones: 5H-pyrano[2,3b:6,5-b’]dipyridin-5-one and 5H-thiopyrano[2,3-b:6,5-b’]dipyridin-5-one, Computed Properties of 71255-09-9, the main research area is pyranodipyridinone; thiopyranodipyridinone; formylation bromopyridine; pyridinecarboxaldehyde conformation.

The title compds (I; X = O, S, resp.) were prepared in 5 and 6 steps, resp., from 3-bromo-2-chloropyridine; yields were excellent. The CO bridge of the diazaxanthones was formed by coupling the aldehydes II (X = O) with 3-lithio-2-methoxypyridine and II (X = S) with 3-lithio-2-(methylthio)pyridine followed by oxidation of the resulting benzylic alc. The other bridge was formed by coupling the 2 ether or sulfide functions with pyridinium-HCl at ∼220°. The conformations of II (X = O, S) are discussed. II (X = O, S) were prepared by treatment of the 3-bromo analogs with BuLi and HCO2Et. I are the 1st reported xanthone-like heterocycles with 2 pyridine rings condensed to the 4-pyrone or -thiopyrone ring.

Journal of Chemical Research, Synopses published new progress about Cyclization. 71255-09-9 belongs to class pyridine-derivatives, name is 2-Methoxynicotinaldehyde, and the molecular formula is C7H7NO2, Computed Properties of 71255-09-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Li, Guoping published the artcilePost-chromatographic dicationic ionic liquid-based charge complexation for highly sensitive analysis of anionic compounds by ultra-high-performance supercritical fluid chromatography coupled with electrospray ionization mass spectrometry, Safety of 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, the main research area is anion analysis UHP supercritical fluid chromatog electrospray ionization MS.

A green anal. strategy has been developed for the anal. of 10 perfluorinated compounds (PFCs) incorporating supramol. solvent (SUPRAS)-based extraction and ultra-high-performance supercritical fluid chromatog. (UHPSFC)-tandem mass spectrometry. The SUPRAS was prepared through self-assembly of reverse micelles by mixing heptanol, THF, and water at optimized volume ratios. An imidazolium-based germinal dicationic ionic liquid (DIL), 1,1-bis(3-methylimidazolium-1-yl) butylene difluoride ([C4(MIM)2]F2), was dissolved in the make-up solvent of UHPSFC and introduced post-column but before the electrospray ionization source. After chromatog. separation on a Torus DIOL anal. column (100 mm x 2.1 mm, 1.7μm), the PFC analytes associated with the DIL reagent through charge complexation. The formation of pos. charged complexes resulted in improved ionization efficiency and anal. sensitivity. Enhancement in signal intensity by one to two magnitudes was achieved in the pos. ionization mode compared to the neg. ionization mode without using the dicationic ion-pairing reagent. The developed protocol was applied to 32 samples of real textiles and 6 samples of real food packaging materials, which exhibited great potential for the anal. of anionic compounds

Analytical Chemistry (Washington, DC, United States) published new progress about Calibration. 36437-30-6 belongs to class pyridine-derivatives, name is 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, and the molecular formula is C26H42Br2N2, Safety of 1,1-Di-n-octyl-4,4-bipyridinium Dibromide.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Barker, John M. published the artcileThienopyridines. Part 7. Some electrophilic substitution reactions of thieno[2,3-b]- and -[3,2-b]pyridine isosteres of 4-oxygenated and 2,4-dioxygenated quinolines, Product Details of C10H9NO4S, the main research area is electrophilic substitution thienopyridine regiochem; quinolinone isostere electrophilic substitution.

Electrophilic substitution reactions were examined of the title compounds I, II [X = NMe, X1 = CO (III); X = CO, X1 = NH (IV), NMe (V)], VI, and VII. The 4-quinolone analogs I and IV, like the parent compound, were monobrominated and (diethylamino)methylated in the pyridine ring α to the CO group. However, whereas 4-quinolone and IV were nitrated in the pyridine ring by HNO3 alone, I was nitrated mainly in the thiophene ring at C-2 under these conditions. The methylated compounds III and V showed a similar regiochem. to their nonmethylated analogs, although their reactivity was lower. I and II were dinitrated by mixed HNO3-H2SO4 at the position α to the CO group in the pyridine ring and at either C-2 in the [2,3-b] isomers (I and III) or C-3 in the [3,2-b] compounds (IV and V); dibromination of I, III, and IV followed a similar pattern. Mannich reactions of VI and VII occurred in the pyridine rings, whereas bromination occurred in the thiophene and pyridine rings in VI and VII, resp.

Journal of Chemical Research, Synopses published new progress about Bromination. 99429-68-2 belongs to class pyridine-derivatives, name is Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, and the molecular formula is C10H9NO4S, Product Details of C10H9NO4S.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem