Month: December 2022

Hopewell, Robert published the artcileA simplified radiosynthesis of [¹⁸F]MK-6240 for tau PET imaging, HPLC of Formula: 17351-61-0, the publication is Journal of Labelled Compounds and Radiopharmaceuticals (2019), 62(2), 109-114, database is CAplus and MEDLINE.

[¹⁸F]MK-6240 (6-(fluoro)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine, I) is a highly selective PET radiotracer for the in vivo imaging of neurofibrillary tangles (NFTs). [¹⁸F]MK-6240 was synthesized in one step from its bis-Boc protected precursor tert-Bu N-[(tert-butoxy)carbonyl]-N-(6-nitro-3-[1H-pyrrolo[2,3-c]pyridin-1-yl]isoquinolin-5-yl)carbamate in DMSO using [¹⁸F] fluoride with TEA HCO₃ with step-wise heating up to 150¡ãC, resulting in an isolated radiochem. yield of 9.8% ¡À 1.8% (n = 3) calculated from the end of bombardment (5.2% ¡À 1.0% calculated from the end of synthesis). This new synthetic approach eliminates the acidic deprotection of the bis-Boc ¹⁸F-labeled intermediate, which reduces the number of operations necessary for the synthesis as well as losses, which occur during deprotection and neutralization of the crude product mixture prior to the HPLC purification The synthesis was performed automatically with a single-use cassette on an IBA Synthera+ synthesis module. This synthesis method affords the radioligand with a reliable radiochem. yield, high radiochem. purity, and a high molar activity. [¹⁸F]MK-6240 synthesized with this method has been regularly (n > 60) used in our ongoing human and animal PET imaging studies.

Journal of Labelled Compounds and Radiopharmaceuticals published new progress about 17351-61-0. 17351-61-0 belongs to catalysis-chemistry, auxiliary class Phase Transfer Catalyst, name is Tetraethylammonium hydrogencarbonate, and the molecular formula is C9H21NO3, HPLC of Formula: 17351-61-0.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Myers, Joseph F. published the artcileSynthesis and study of a nickel(II) complex containing a macrocyclic ligand derived from 1,3-diaminopropane and methyl vinyl ketone1, Name: Propane-1,3-diamine dihydrochloride, the publication is Inorganic Chemistry (1973), 12(6), 1238-45, database is CAplus.

The macrocyclic complex I can be synthesized from 1,3-diaminopropane and Me vinyl ketone in the presence of both Ni(II) and H ions. Several derivatives of I are described including 2 where the macrocyclic ligand must be present in a folded configuration within a 6-coordinate complex. The detailed description of the separation and purification of 2 interconvertible isomeric complexes is presented. These isomers are the meso and racemic forms.

Inorganic Chemistry published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Name: Propane-1,3-diamine dihydrochloride.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Gholivand, M. B. published the artcileHighly sensitive and selective measurement of bismuth in seawater and drug with 1,2-phenylenedioxydiacetic acid by cathodic adsorptive stripping voltammetry, Formula: C10H10O6, the publication is Electroanalysis (2006), 18(7), 730-734, database is CAplus.

A new method is presented for determination of Bi based on cathodic adsorptive stripping of complex Bi with 1,2-phenylenedioxydiacetic acid (PDA) at a hanging mercury drop electrode (HMDE). The effect of various parameters such as pH, concentration of ligand, accumulation potential and accumulation time on the selectivity and sensitivity were studied. The optimum conditions for determination of Bi include HNO₃ concentration 0.01 M, 8.0 ¡Á 10^-4 M PDA and accumulation time 120 s, accumulation potential of -200 mV. The limits of detection are 0.25 and 0.05 nM, and responses are linear 1-1000 and 0.1-400 nM at t_acc of 60 and 120 s, resp. Many common anions and cations do not interfere in the determination of Bi. The method was applied to the determination of Bi in some real samples such as sea- and spring water and drug.

Electroanalysis published new progress about 5411-14-3. 5411-14-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2,2-(1,2-Phenylenebis(oxy))diacetic acid, and the molecular formula is C10H10O6, Formula: C10H10O6.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Schermuly, Isabel I. published the artcileDietary methionine source alters the lipidome in the small intestinal epithelium of pigs, Application In Synthesis of 63-68-3, the publication is Scientific Reports (2022), 12(1), 4863, database is CAplus and MEDLINE.

Methionine (Met) as an essential amino acid has key importance in a variety of metabolic pathways. This study investigated the influence of three dietary Met supplements (0.21% L-Met, 0.21% DL-Met and 0.31% DL-2-hydroxy-4-(methylthio)butanoic acid (DL-HMTBA)) on the metabolome and inflammatory status in the small intestine of pigs. Epithelia from duodenum, proximal jejunum, middle jejunum and ileum were subjected to metabolomics anal. and qRT-PCR of caspase 1, NLR family pyrin domain containing 3 (NLRP3), interleukins IL1¦Â, IL8, IL18, and transforming growth factor TGF¦Â. Principal component anal. of the intraepithelial metabolome revealed strong clustering of samples by intestinal segment but not by dietary treatment. However, pathway enrichment anal. revealed that after L-Met supplementation polyunsaturated fatty acids (PUFA) and tocopherol metabolites were lower across small intestinal segments, whereas monohydroxy fatty acids were increased in distal small intestine. Pigs supplemented with DL-HMTBA showed a pronounced shift of secondary bile acids (BA) and sphingosine metabolites from middle jejunum to ileum. In the amino acid super pathway, only histidine metabolism tended to be altered in DL-Met-supplemented pigs. Diet did not affect the expression of inflammation-related genes. These findings suggest that dietary supplementation of young pigs with different Met sources selectively alters lipid metabolism without consequences for inflammatory status.

Scientific Reports published new progress about 63-68-3. 63-68-3 belongs to catalysis-chemistry, auxiliary class Natural product, name is (S)-2-Amino-4-(methylthio)butanoic acid, and the molecular formula is C5H11NO2S, Application In Synthesis of 63-68-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Souto, Jose A. published the artcileSynthetic studies on alotamide A: construction of N-demethylalotamide A, SDS of cas: 71989-31-6, the publication is European Journal of Organic Chemistry (2021), 2021(44), 6057-6070, database is CAplus.

Several approaches to the synthesis of cyclodepsipeptide natural product alotamide A are described, eventually affording a very advanced N-demethylated analog of the targeted natural product. The difficulties found in our endeavors on the synthesis of alotamide A have allowed us to gather some valuable information regarding the most convenient synthetic step for each key transformation. The intramol. Csp²-Csp² Stille cross-coupling and the macrolactam formation were found to be reliable protocols for the final construction of the alotamide A skeleton.

European Journal of Organic Chemistry published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C15H14N2, SDS of cas: 71989-31-6.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Bellini, Clement published the artcileSequential Barium-Catalysed N-H/H-Si Dehydrogenative Cross-Couplings: Cyclodisilazanes versus Linear Oligosilazanes, Application In Synthesis of 140-28-3, the publication is Chemistry – A European Journal (2016), 22(44), 15733-15743, database is CAplus and MEDLINE.

Starting from Ph₃SiH, the barium precatalyst Ba[CH(SiMe₃)₂]₂¡¤(THF)₃ was used to produce the disilazane Ph₃SiN(Bn)SiPh₂NHBn (4) by sequential N-H/H-Si dehydrogenative couplings with BnNH₂ and Ph₂SiH₂. Substrate scope was extended to other amines and hydrosilanes. This smooth protocol gives quant. yields and full chemoselectivity. Compound 4 and the intermediates Ph₃SiNHBn and Ph₃SiN(Bn)SiHPh₂ were structurally characterized. Further attempts at chain extension by dehydrocoupling of Ph₂SiH₂ with 4 instead resulted in cyclization of this compound, forming the cyclodisilazane c-(Ph₂Si-NBn)₂ (5) which was crystallog. authenticated. The ring-closure mechanism leading to 5 upon release of C₆H₆ was determined by complementary exptl. and theor. (DFT) investigations. Ba[CH(SiMe₃)₂]₂¡¤(THF)₃ and 4 react to afford the reactive Ba{N(Bn)SiPh₂N(Bn)SiPh₃}₂, which was characterized in situ by NMR spectroscopy. Next, in a stepwise process, intramol. nucleophilic attack of the metal-bound amide on the terminal silicon atom generates a five-coordinate silicate. It is followed by turnover-limiting ¦Â-C₆H₅ transfer to barium; this releases 5 and forms a transient [Ba]-Ph species, which undergoes aminolysis to regenerate [Ba]-N(Bn)SiPh₂N(Bn)SiPh₃. DFT computations reveal that the irreversible production of 5 through such a stepwise ring-closure mechanism is much more kinetically facile (¦¤G^¡Ù=26.2 kcal mol^-1) than an alternative ¦Ò-metathesis pathway (¦¤G^¡Ù=48.2 kcal mol^-1).

Chemistry – A European Journal published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C16H20N2, Application In Synthesis of 140-28-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Bardin, V. V. published the artcileReactions of trimethylsilylpentafluorobenzene and triethylgermylpentafluorobenzene with nucleophilic reagents, Name: Trimethyl(perfluorophenyl)silane, the publication is Journal of Fluorine Chemistry (1992), 59(2), 165-77, database is CAplus.

The reactions of trialkylsilyl- and (trialkylgermyl)pentafluorobenzenes with O-, N, S- and C-nucleophiles, and with LiAlH₄ are reported. Depending on the nature of the nucleophilic reagent, its attacked is oriented towards a heteroatom (RO^–, RS^–), the C-4 atom of the pentafluorophenyl ring (BuLi, LiAlH₄, piperidyllithium) or at both electrophilic centers (piperidine, RS^–).

Journal of Fluorine Chemistry published new progress about 1206-46-8. 1206-46-8 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Trimethyl(perfluorophenyl)silane, and the molecular formula is C9H9F5Si, Name: Trimethyl(perfluorophenyl)silane.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Curtis, N. J. published the artcileDetermination of derivatives of diphenylamine in Australian gun propellants by high performance liquid chromatography, Application of Bis(4-nitrophenyl)amine, the publication is Propellants, Explosives, Pyrotechnics (1987), 12(5), 158-63, database is CAplus.

HPLC was developed for the determination of diphenylamine and its N-nitroso- and C-nitro derivatives in single-base gun propellants. Only 2- and 4-nitrodiphenylamine, 2,2′-, 2,4′- and 4,4′-dinitrodiphenylamine, 2,2′,4- and 2,4,4′-trinitrodiphenylamine, 2,2′,4,4′-tetranitrodiphenylamine, N-nitrosodiphenylamine, and 4-nitro-N-nitrosodiphenylamine were found in major amounts Minor derivatives noted were 2,4′-dinitrodiphenylamine, 2-nitro-N-nitrosodiphenylamine, and 2,4′- and 4,4′-dinitro-N-nitrosodiphenylamine. Other derivatives were not found. This HPLC method can be used to quantify all of the major derivatives in a single chromatogram and can be used even in the presence of the propellant additives dinitrotoluene, bis(ethylhexyl) phthalate, and di-Bu phthalate.

Propellants, Explosives, Pyrotechnics published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C12H9N3O4, Application of Bis(4-nitrophenyl)amine.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Du, Lufan published the artcileOrganic crystal-based THz source for complex refractive index measurements of window materials using single-shot THz spectroscopy, COA of Formula: C14H14N2O2, the publication is Applied Physics A: Materials Science & Processing (2021), 127(11), 846, database is CAplus.

We employed N-benzyl-2-methyl-4-nitroaniline (BNA) crystals bonded on substrates of different thermal conductivity to generate THz radiation by pumping with 800 nm laser pulses. Crystals bonded on sapphire substrate provided four times more THz yield than glass substrate. A pyrodetector and a single-shot electro-optic (EO) diagnostic were employed for measuring the energy and temporal characterization of the THz pulse. Systematic studies were carried out for the selection of a suitable EO crystal, which allowed accurate determination of the emitted THz spectrum from both substrates. Subsequently, the THz source and single-shot electro-optic detection scheme were employed to measure the complex refractive index of window materials in the THz range.

Applied Physics A: Materials Science & Processing published new progress about 201157-13-3. 201157-13-3 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is N-Benzyl-2-methyl-4-nitroaniline, and the molecular formula is C14H14N2O2, COA of Formula: C14H14N2O2.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Koshkin, L. V. published the artcileAntioxidative effectiveness of secondary aromatic amines in the oxidation of SKS 30 ARK rubber, Application of Bis(4-nitrophenyl)amine, the publication is Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya (1985), 28(8), 97-100, database is CAplus.

The effectiveness of aromatic amines as antioxidants for SKS 30ARK (SBR) increased with increasing electron donor properties of para substituents (Br, Me, OMe, NMe₂) on the Ph rings, with increasing ¦Ð electron d. of the aromatic rings, and on introducing ortho or para NO₂ groups in Ph₂NH. The antioxidative action of the nitro derivatives was attributed to interaction of the NO₂ groups with C radicals of the oxidizing polymer. Other amines interacted with O radicals. A synergistic antioxidative effect was observed for mixts of p-O₂NC₆H₄NHPh [836-30-6] and N-¦Â-naphthyl-N-phenylamine??[135-88-6].

Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C12H9N3O4, Application of Bis(4-nitrophenyl)amine.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia