Month: December 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

Yu, Weiqun published the artcileReviving Cav1.2 as an attractive drug target to treat bladder dysfunction, Name: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, the publication is FASEB Journal (2022), 36(1), e22118, database is CAplus and MEDLINE.

A review. Inhibition of bladder contraction with antimuscarinics is a common approach to treat bladder hyperactivity, and the L-type voltage-gated calcium channel α1C (Cav1.2) is crucial for bladder contractility. Therefore, strategies aimed at inhibiting Cav1.2 appear warranted. However, multiple clin. trials that attempted to treat bladder overactivity with calcium channel blockers (CCBs) have been unsuccessful, creating an unsolved mystery. In contrast, cardiologists and epidemiologists have reported strong associations between CCB use and bladder hyperactivity, opposing expectations of urologists. Recent findings from our lab offer a potential explanation. We have demonstrated that ketamine which can cause cystitis, functions, like nifedipine, as a Cav1.2 antagonist. We also show that a Cav1.2 agonist which potentiates muscle contraction, rather than antagonizing it, can increase the volume of voids and reduce voiding frequency. This perspective will discuss in detail the unsuccessful urol. trials of CCBs and the promise of Cav1.2 agonists as potential novel therapies for bladder dysfunctions.

FASEB Journal published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C16H20N2, Name: Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Watanabe, Takashi published the artcileOrganic synthesis unit process-thiochemicals and heterocyclic compounds: heterocyclic compounds (part 1), Quality Control of 636-73-7, the publication is Fain Kemikaru (2013), 42(8), 53-66, database is CAplus.

Unit processes of various heterocyclic compounds including furan derivatives, THF or its derivatives, chroman, thiophene or its derivatives, tetrahydrothiophene, pyrrole or its derivatives, pyrrolidine or its derivatives, indole derivative, pyridine derivatives, piperidine derivatives, and quinoline or its derivatives are described. Thus, 2,6-dibromo-4-nitrophenol 8, glycerin 20, and concentrated H₃PO₄ 12 g were charged to a 3-neck flask fitted with a stirrer, a reflux condenser, and a thermometer, cooled, treated slowly with concentrated H₂SO₄ with stirring well, heated in a oil bath at 150-160° for 3 h with gentle refluxing, and cooled. Water (∼150 mL) was added to the flask content solidified, throughly pulverized, and filtered to sep. the insoluble residue and the filtrate. The insoluble residue was immersed in warm 5% aqueous HCl solution and left to be cooled to readily precipitate colorless needle crystals which were filtered off. The filtrate was concentrated to give addnl. crystalline salt. The combined crystalline salt (3.55 g) was added to slightly acidic aqueous Na₂CO₃ solution, throughly stirred, left to stand for ∼20 min, and the free amine formed (2.87 g) was filtered off and recrystallized from acetone to give 7-bromo-6-hydroxyquinoline. The filtrate from the aqueous Na₂CO₃ solution was neutralized with Na₂CO₃, followed by filtering off the precipitated free amine (0.72 g) and recrystallization from acetone to give 7-bromo-6-hydroxyquinoline in ∼62% as crude product.

Fain Kemikaru published new progress about 636-73-7. 636-73-7 belongs to pyridine-derivatives, auxiliary class Pyridine,Sulfonic acid, name is Pyridine-3-sulfonic acid, and the molecular formula is C4H7BN2O2, Quality Control of 636-73-7.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Vecchio-Sadus, Angelica M. published the artcileElectrochemical synthesis of neutral transition metal(II) (Fe, Co, Ni, Cu, Zn) complexes of pyridine-2-carbaldehyde pyridine-2′-ylhydrazone and several analogs, SDS of cas: 2215-33-0, the publication is Transition Metal Chemistry (London) (1995), 20(3), 256-61, database is CAplus.

Neutral transition metal(II) complexes of pyridine-2-carbaldehyde pyridine-2′-ylhydrazone (papyH) and several analogs were prepared by electrochem. synthesis. [M(papy)₂] (M = Fe, Co, Ni, Cu or Zn) were obtained mostly as red-green dichroic substances as a result of the extended π-conjugation system in the anionic hydrazone. Vibrational and electronic spectra confirm the presence of the anionic hydrazone and its tridentate coordination to the metal center.

Transition Metal Chemistry (London) published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C4Br2N2O4S, SDS of cas: 2215-33-0.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Vecchio-Sadus, Angelica M. published the artcileElectrosynthesis and magnetic behavior of neutral cobalt(II) complexes of pyridine-2-carbaldehyde pyridin-2′-ylhydrazone (papyH) and its analogs, Category: pyridine-derivatives, the publication is Transition Metal Chemistry (London) (1995), 20(1), 38-45, database is CAplus.

Neutral cobalt(II) complexes with the tridentate N-heterocyclic ligand pyridine-2-carbaldehyde pyridin-2′-ylhydrazone (papyH) and its analogs were prepared by the electrochem. oxidation of cobalt in an acetone solution of the hydrazone. [Co(papy)₂] were obtained as red-green dichroic microcrystals due to the extended π-conjugation system in the anionic ligand. The magnetic moments of the octahedral cobalt(II) chelates decrease continuously from μ_eff = 1.81-4.63 μB at room temperature to 1.7-4.08 μB at ∼90 K. The changes in magnetic moment were accounted for by a ⁴T₁ ↔ ²E spin crossover system.

Transition Metal Chemistry (London) published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C4Br2N2O4S, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Updegraff, D. M. published the artcileTriarylborane complexes, a new series of broad-spectrum germicides, Application of Triphenyl(pyridin-1-ium-1-yl)borate, the publication is Journal of Infectious Diseases (1964), 304-10, database is CAplus.

More than 100 coordination complexes of triarylboranes with amines and substituted phosphines were screened against bacteria and fungi, and selected members were also screened against protozoa. The chem. stable complexes of triphenylborane and tris(para-substituted phenyl)borane were powerful broad-spectrum germicides, fungicides, and protozoicides.

Journal of Infectious Diseases published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C19H22BNO5, Application of Triphenyl(pyridin-1-ium-1-yl)borate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Torssell, Kurt published the artcilePositive halogen compounds. VI. Preparation of alkoxydimethylsulfonium salts and their role in the Kornblum oxidation. Revision of the structure for the olefin-bromotrinitromethane adduct, Quality Control of 971-66-4, the publication is Acta Chemica Scandinavica (1947-1973) (1967), 21(1), 1-14, database is CAplus.

cf. CA 63: 6839b; 65: 19963b. Structure I for the reaction product of BrC(NO2)3 and cyclohexene was revised to II (R = 2-trans-bromocyclohexyl) (III). Treatment of 0.2 g. III in 1 ml. EtOAc with 0.2 g. NaBPh4 gave ROS+Me2B-Ph4 (IV, R = 2-bromocyclohexyl) (V), m. 138-40° (decomposition). III (0.2 g.) was heated with 1 ml. iso-BuOH at 55-6° 45 min. and treated with 0.2 g. NaBPh4 in 1 ml. EtOAc to give 0.19 g. IV (R = iso-Bu) (VI) m. 141-3° (decomposition). ClCO2Bu-iso prepared from 0.16 g. iso-BuOH and a slight excess of COCl2 (10% in ether) was treated, after evaporation of ether, with 1 ml. Me2SO and, after 0.5 hr., 0.7 g. NaBPh4 in 6 ml. 1:1 MeOH-water mixture to give 0.4 g. IV (R = Et), m. 150-60°, remelts ∼260°. III (1 g.) in 4 ml. MeOH kept at 40-50° 20 min., evaporated to half volume in vacuo, and treated with 10 ml. CCl4 to give 0.55 g. II (R = Me). II (R = Me) (0.25 g.) in 1 ml. MeOH was treated with 0.4 g. NaBPh4 in 1 ml. MeOH to give 0.38 g. IV (R = Me) (VII). Me2SO (0.3 g.) was mixed with 0.5 g. Me2SO4, kept at room temperature 24 hrs., treated with 0.75 g. KC(NO2)3 in 5 ml. dimethoxyethane, filtered from KMeSO4, concentrated to 0.5 volume in vacuo, and treated with 10 ml. CCl4 to give 0.3 g. VII, m. 51-2° (decomposition). Treatment of a mixture of 0.5 g. Me2SO4 and 0.3 g. Me2SO with 1.4 g. NaBPh4 in 10 ml. MeOH gave 0.9 g. VII. A bromonium ion (VIII) is suggested. VII (0.2 g.) was heated to 190° in a small bulb tube until gas evolution ceased (∼10 min.) to give 40 mg. condensate composed of benzene and MeOCH2SMe (ir and N.M.R.); the remainder was partially crystalline and gave Ph3BOSMe2 (IX), m. 160-3°. IX can also be obtained by addition of 0.1 ml. concentrated HCl to 0.2 g. NaBPh4 in 2 ml. water. Treatment of 50 mg. IX in 3 ml. EtOAc with 50 mg. pyridine gave Ph3BQ (Q = 1-pyridyl), m. 210° (decomposition), which was also obtained by Pfitzner-Moffat oxidation Pyrolysis of V at 130-40° 5 min. gave mostly benzene and a small amount IX, and pyrolysis of V in Me2SO gave a somewhat higher yield of carbonyl compounds and trans-2-bromocyclohexanol. Thus, the Kornblum oxidation and Barton’s modification (CA 61: 2958e) proceeds via an intermediary sulfonium ion, which collapses to a carbonyl compound and Me2S either by the reaction (1) or a cyclic mechanism (2), giving Me2S and CD3SCD2H when Me2CHCH2OS+(CD3)2B-Ph4 was pyrolyzed. The oxidation follows the mechanism (1) only if the α-proton is activated as in p-BrC6H4COCH2OS+Me2. A mechanism (3) for Pfitzner and Moffat oxidation (CA 64: 6709g) was suggested to proceed via a complex (X). Magnetic nonequivalence for S-methyl resonance peak of V (a doublet, separation 1.7 Hz.) was found. N.M.R. spectrum of VII or II (R = Me) underwent a drastic change when the compounds were heated in (CD3)2SO at 65°. After 1 hr., the absorption of SMe at δ = 3.29 disappeared and a new peak appeared at δ = 2.57 ppm. The peak at δ = 3.97 ppm. had the same intensity as before and only traces of Me2S were detected. The result suggested a carbonium ion exchange (4) comparable with proton exchange in water. The reaction is completely reversible because when XI was dissolved in Me2SO, VII was regenerated. Addition of NaI to VII gave a rapid change of spectrum showing a reaction, Me2SO+Me + NaI → Me2SO + MeI + Na+. Pyrolysis of VII to MeOCH2SMe resembles the Pummerer rearrangement.

Acta Chemica Scandinavica (1947-1973) published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C10H10CoF6P, Quality Control of 971-66-4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem