Category: 17351-62-1

Castillo Melean, Johnny published the artcileA three-step radiosynthesis of 6-[¹⁸ F]fluoro-L-meta-tyrosine starting with [¹⁸ F]fluoride, COA of Formula: C17H37NO3, the publication is Journal of Labelled Compounds and Radiopharmaceuticals (2015), 58(3), 133-140, database is CAplus and MEDLINE.

The radiosynthesis of 6-[¹⁸ F]fluoro-L–m-tyrosine has generally been performed by electrophilic radiofluorination, which exhibits several drawbacks. In the present work, a three-step radiochem. synthesis is described starting from [¹⁸ F]fluoride. The synthetic sequence, including isotopic exchange, Baeyer-Villiger oxidation, and hydrolysis, were examined comparing four fluorobenzophenone derivatives as labeling precursors. Of those, (2S,5S)-tert-Bu 5-(5-acetyl-2-fluorobenzyl)-2-tert-butyl-3-methyl-4-oxoimidazolidine-1-carboxylate and (2S,5S)-tert-Bu 2-tert-butyl-5-(2-fluoro-5-(2,2,2-trifluoroacetyl)benzyl)-3-methyl-4-oxoimidazolidine-1-carboxylate proved to be the most suitable ones. 6-[¹⁸ F]Fluoro-L-m-tyrosine was obtained with overall radiochem. yields of 8-13% and an enantiomeric excess of up to 98%.

Journal of Labelled Compounds and Radiopharmaceuticals published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, COA of Formula: C17H37NO3.

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

Castillo Melean, Johnny published the artcileEnantiospecific synthesis of 2-[¹⁸F]fluoro-L-phenylalanine and 2-[¹⁸F]fluoro-L-tyrosine by isotopic exchange, Category: catalysis-chemistry, the publication is Organic & Biomolecular Chemistry (2011), 9(3), 765-769, database is CAplus and MEDLINE.

2-[¹⁸F]Fluoro-L-phenylalanine and 2-[¹⁸F]fluoro-L-tyrosine have been developed as promising radiopharmaceuticals for mol. imaging using positron emission tomog. (PET). However, the lack of a convenient radiosynthetic pathway has limited their practical use. In this work a new three-step nucleophilic synthesis of these compounds starting from [¹⁸F]fluoride is described. Corresponding precursors (I) (R¹ = H or OCH₂Ph; Boc = tert-butoxycarbonyl) were ¹⁸F-fluorinated by isotopic exchange, followed by the removal of an activating formyl group with Rh(PPh₃)₃Cl and subsequent hydrolysis of protecting groups in acidic medium. All reactions were carried out using both conventional and microwave heating. Conventional heated reactions yielded the desired products 2-[¹⁸F]Fphe and 2-[¹⁸F]Ftyr in 43% and 49% whereas radiochem. yields of 34% and 43%, resp., were obtained when they were heated by microwaves. Under optimized conditions the enantiomeric purity was ¡Ý94% for both radiopharmaceuticals.

Organic & Biomolecular Chemistry published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Category: catalysis-chemistry.

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

Bose, Purnandhu published the artcileCombined Solution-Phase, Solid-Phase and Phase-Interface Anion Binding and Extraction Studies by a Simple Tripodal Thiourea Receptor, Application of Tetrabutylammonium hydrogencarbonate, the publication is European Journal of Inorganic Chemistry (2012), 2012(35), 5791-5801, database is CAplus.

Tris(2-aminoethyl)amine (tren) based 4-cyanophenyl-substituted tripodal L, tris{[(4-cyanophenyl)amino]ethyl}thiourea receptor, was synthesized and explored thoroughly for anion recognition in solution by NMR spectroscopy and isothermal titration calorimetry (ITC) as well as in the solid state by single-crystal X-ray diffraction studies. Anion recognition properties of L were further exploited toward the extraction of sulfate as well as fluoride from aqueous media using a liquid-liquid extraction technique. A solution-state anion binding study using NMR spectroscopy in [D₆]DMSO and ITC measurements in dry acetonitrile show a relatively higher association constant of L with halides (F^– and Cl^–) over oxyanions (H₂PO₄^– and HSO₄^–). The single-crystal X-ray structural anal. of complex 1 reveals a monotopic encapsulation of fluoride in L through six N-H¡¤¡¤¡¤F^– interactions with a distorted trigonal-prismatic geometry, whereas sulfate and carbonate induce dimeric assemblies of L in complexes 2 and 3, resp. In the case of sulfate, a tight dimeric capsular assembly of ca. 9.5 ? is observed through 15 N-H¡¤¡¤¡¤O interactions, whereas carbonate forms a sandwich-like dimeric mol. aggregation through 14 N-H¡¤¡¤¡¤O interactions. In the presence of tetrabutylammonium iodide as the phase transfer agent, L has shown ca. 70 % extraction of fluoride (based on L) and ca. 40 % extraction of sulfate (based on L) from aqueous solutions using an anion-exchange-based liquid-liquid extraction strategy. Extraction of these anions is unambiguously demonstrated by ¹H NMR, ¹⁹F NMR and FTIR spectroscopy, PXRD and single-crystal X-ray diffraction studies.

European Journal of Inorganic Chemistry published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Application of Tetrabutylammonium hydrogencarbonate.

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

Gomez, Antonio Bermejo published the artcileEfficient DBU accelerated synthesis of ¹⁸F-labelled trifluoroacetamides, Safety of Tetrabutylammonium hydrogencarbonate, the publication is Chemical Communications (Cambridge, United Kingdom) (2016), 52(97), 13963-13966, database is CAplus and MEDLINE.

Nucleophilic ¹⁸F-fluorination of bromodifluoromethyl derivatives was performed using [¹⁸F]Bu₄NF in the presence of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). This novel procedure provided a diverse set of [¹⁸F]trifluoroacetamides in good to excellent radiochem. conversions. A mechanism where DBU acts as organomediator in this transformation is proposed.

Chemical Communications (Cambridge, United Kingdom) published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Safety of Tetrabutylammonium hydrogencarbonate.

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

Alauddin, Mian M. published the artcileSynthesis of [¹⁸F]-labeled 2′-deoxy-2′-fluoro-5-methyl-1-¦Â-D-arabinofuranosyluracil ([¹⁸F]-FMAU), Safety of Tetrabutylammonium hydrogencarbonate, the publication is Journal of Labelled Compounds & Radiopharmaceuticals (2002), 45(7), 583-590, database is CAplus.

Synthesis of 2′-deoxy-2′-[¹⁸F]fluoro-5-methyl-1-¦Â-D- arabinofuranosyluracil ([¹⁸F]-FMAU) is reported. 2-Deoxy-2-[¹⁸F]fluoro-1,3,5-tri-O-benzoyl-¦Á-D-arabinofuranose was prepared by the reaction of the resp. triflate with tetrabutylammonium[¹⁸F]fluoride. The fluorosugar was converted to its 1-bromo-derivative and coupled with protected thymine. The crude product mixture was hydrolyzed in base and purified by HPLC to obtain the radiolabeled FMAU (I). The radiochem. yield of I was 20-30% decay corrected (d.c.) in four steps with an average of 25% in four runs. Radiochem. purity was >99% and average specific activity was 2300 mCi/¦Ìmol at the end of synthesis (EOS). The synthesis time was 3.5-4.0h from the end of bombardment (EOB).

Journal of Labelled Compounds & Radiopharmaceuticals published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Safety of Tetrabutylammonium hydrogencarbonate.

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

Gail, R. published the artcileA one step preparation of the n.c.a. fluorine-18 labeled synthons: 4-fluorobromobenzene and 4-fluoroiodobenzene, Synthetic Route of 17351-62-1, the publication is Applied Radiation and Isotopes (1994), 45(1), 105-11, database is CAplus.

4-¹⁸FC₆H₄X (X = Br, iodo) are interesting precursors for organometallic nucleophilic reagents. A 1-step preparation of these synthons was achieved by no-carrier-added (n.c.a.) nucleophilic exchange on the corresponding 4-bromo- and 4-iodophenyltrimethylammonium salts. The leaving ability of the trimethylammonium group increases strongly with decreasing basicity of the counteranion in the sequence: tosylate < Me sulfate < iodide < perchlorate (no data) < triflate. Systematic optimization leads to radiochem. yields of 50 ¡À 5% and 80 ¡À 5% within 5 min for the bromo and iodo derivs, resp., in AcNMe₂ as the solvent.

Applied Radiation and Isotopes published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Synthetic Route of 17351-62-1.

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

Tay, Nicholas E. S. published the artcile¹⁹F- and ¹⁸F-arene deoxyfluorination via organic photoredox-catalysed polarity-reversed nucleophilic aromatic substitution, SDS of cas: 17351-62-1, the publication is Nature Catalysis (2020), 3(9), 734-742, database is CAplus and MEDLINE.

Nucleophilic aromatic substitution (S_NAr) is routinely used to install ¹⁹F- and ¹⁸F- in aromatic mols., but it is typically limited to electron-deficient arenes due to kinetic barriers associated with C-F bond formation. A polarity-reversed photoredox-catalyzed arene deoxyfluorination that operates via cation-radical-accelerated S_NAr enables the fluorination of electron-rich arenes 4-ClC₆H₄OR (R = 4-phenylphenyl, 3-methoxypyridin-2-yl, 2,4-bis(tert-butoxy)pyrimidin-5-yl, 4-[(2S)-2-([(tert-butoxy)carbonyl]amino)-3-methoxy-3-oxopropyl]benzen-1-yl, etc.) with ¹⁹F- and ¹⁸F- under mild conditions, and thus complements the traditional arene polarity requirements necessary for S_NAr-based fluorination. The utility of radiofluorination strategy is highlighted by short reaction times, compatibility with multiple nucleofuges and high radiofluorination yields ¹⁸FR, especially that of an important cancer positron emission tomog. agent [¹⁸F]5-fluorouracil. Taken together, fluorination approach enables the development of fluorinated ¹⁹FR and radiofluorinated compounds ¹⁸FR that can be difficult to access by classical S_NAr strategies, with the potential for use in the synthesis and discovery of positron emission tomog. radiopharmaceuticals.

Nature Catalysis published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C10H11NO4, SDS of cas: 17351-62-1.

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

Wang, Jia published the artcilePerforming multi-step chemical reactions in microliter-sized droplets by leveraging a simple passive transport mechanism, Recommanded Product: Tetrabutylammonium hydrogencarbonate, the publication is Lab on a Chip (2017), 17(24), 4342-4355, database is CAplus and MEDLINE.

Despite the increasing importance of positron emission tomog. (PET) imaging in research and clin. management of disease, access to myriad new radioactive tracers is severely limited due to their short half-lives (which requires daily production) and the high cost and complexity of tracer production The application of droplet microfluidics based on electrowetting-on-dielec. (EWOD) to the field of radiochem. can significantly reduce the amount of radiation shielding necessary for safety and the amount of precursor and other reagents needed for the synthesis. Furthermore, significant improvements in the molar activity of the tracers have been observed However, widespread use of this technol. is currently hindered in part by the high cost of prototype chips and the operating complexity. To address these issues, we developed a novel microfluidic device based on patterned wettability for multi-step radiochem. reactions in microliter droplets and implemented automated systems for reagent loading and collection of the crude product after synthesis. In this paper, we describe a simple and inexpensive method for fabricating the chips, demonstrate the feasibility of prototype chips for performing multi-step radiochem. reactions to produce the PET tracers [¹⁸F]fallypride and [¹⁸F]FDG, and further show that synthesized [¹⁸F]fallypride can be used for in vivo mouse imaging.

Lab on a Chip published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C8H14O4, Recommanded Product: Tetrabutylammonium hydrogencarbonate.

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

Hohn, Michael published the artcileSynthesis and Preliminary In Vitro and In Vivo Evaluation of Thiirane-Based Slow-Binding MMP Inhibitors as Potential Radiotracers for PET Imaging, Category: catalysis-chemistry, the publication is ChemistrySelect (2018), 3(42), 11729-11736, database is CAplus.

Many serious diseases such as cancer, atherosclerosis and arthritis are characterized by upregulation of activated matrix metalloproteinases (MMPs). For this reason imaging and quantification of activated MMPs with the mol. imaging techniques such as single photon emission computed tomog. (SPECT) and positron emission tomog. (PET) using radiolabeled MMP inhibitors would be a valuable tool for the diagnosis and therapy planning of mentioned diseases. This work aims at the synthesis and preliminary in vitro and in vivo evaluation of positron-emitter 18F-fluorine labeled radiotracers based on 2-{[(4-phenoxyphenyl)sulfonyl]methyl}thiirane (SB-3CT), a slow-binding and mechanism-based MMP-2 and -9 inhibitor. Therefore, a library of fluorinated SB-3CT derivatives were prepared and evaluated in vitro in MMP inhibition assays. From this pool the 18F-labeled triazole [18F]18d was successfully synthesized in a two-step procedure. However, this compound was unstable in human and mouse serum and showed a biodistribution behavior in C57BL/6 mice that is not favorable for PET imaging preventing further in vivo evaluations in MMP-associated mouse models of disease.

ChemistrySelect published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Category: catalysis-chemistry.

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

Zhang, Hanwen published the artcileAn improved strategy for the synthesis of [¹⁸F]-labeled arabinofuranosyl nucleosides, Category: catalysis-chemistry, the publication is Nuclear Medicine and Biology (2012), 39(8), 1182-1188, database is CAplus and MEDLINE.

The expression of the herpes simplex virus type-1 thymidine kinase (HSV1-tk) gene can be imaged efficaciously using a variety of 2′-[¹⁸F]fluoro-2′-deoxy-1-¦Â-D-arabinofuranosyl-uracil derivatives [¹⁸F]-F(X)AU (X = I, Et, Me), e.g. I. However, the application of these derivatives in clin. and translational studies has been impeded by their complicated and long syntheses (3-5 h). To remedy these issues, in the study at hand we have investigated whether microwave or combined catalysts could facilitate the coupling reaction between sugar and nucleobase and, further, have probed the feasibility of establishing a novel approach for [¹⁸F]-F(X)AU synthesis. We have demonstrated that the rate of the trimethylsilyl trifluoromethanesulfonate (TMSOTf)-catalyzed coupling reaction between the 2-deoxy-sugar and uracil derivatives at 90 ¡ãC can be significantly accelerated by microwave-driven heating or by the addition of Lewis acid catalyst (SnCl₄). Further, we have observed that the stability of the ¦Á- and ¦Â-anomers of [¹⁸F]-F(X)AU derivatives differs during the hydrolysis step. Using the microwave-driven heating approach, overall decay-corrected radiochem. yields of 19%-27% were achieved for [¹⁸F]-FXAU in 120 min at a specific activity of > 22 MBq/nmol (595 Ci/mmol). Ultimately, we believe that these high yielding syntheses of [¹⁸F]-F(I)AU, [¹⁸F]-F(Me)AU and [¹⁸F]-F(Et)AU will facilitate routine production for clin. applications.

Nuclear Medicine and Biology published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C8H7ClO3, Category: catalysis-chemistry.

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