- A practical microwave method for the synthesis of fluoromethy 4-methylbenzenesulfonate in tert-amyl alcohol
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Fluorine substitution is an established tool in medicinal chemistry to favourably alter the molecular properties of a lead compound of interest. However, gaps still exist in the library of synthetic methods for accessing certain fluorine-substituted motifs. One such area is the fluoromethyl group, particularly when required in a fluoroalkylating capacity. The cold fluorination of methylene ditosylate is under evaluated in the literature, often proceeding with low yields or harsh conditions. This report describes a novel microwave method for the rapid nucleophilic fluorination of methylene ditosylate using inexpensive reagents in good isolated yield (65%).
- Brocklesby, Kayleigh L.,Waby, Jennifer S.,Cawthorne, Christopher,Smith, Graham
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Read Online
- Automated synthesis and purification of [18F]fluoro-[di-deutero] methyl tosylate
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Automated synthetic procedures of [18F]fluoro-[di-deutero]methyl tosylate on a GE TRACERlab FX F-N module and a non-commercial synthesis module have been developed. The syntheses included azeotropic drying of the [ 18F]fluoride, nucleophilic 18F-fluorination of bis(tosyloxy)-[di-deutero]methane, HPLC purification and subsequent formulation of the synthesized [18F]fluoro-[di-deutero]methyl tosylate (d 2-[18F]FMT) in organic solvents. Automation shortened the total synthesis time to 50 min, resulting in an average radiochemical yield of about 50% and high radiochemical purity (>98%). The possible application of this procedure to commercially available synthesis modules might be of significance for the production of deuterated 18F-fluoromethylated imaging probes in the future. Copyright
- Beyerlein, Friederike,Piel, Markus,Hoehnemann, Sabine,Roesch, Frank
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Read Online
- Monofluoromethyl-Substituted Sulfonium Ylides: Electrophilic Monofluoromethylating Reagents with Broad Substrate Scopes
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Two electrophilic monofluoromethylating reagents, monofluoromethyl(phenyl)sulfonium bis(carbomethoxy)methylide (3 a) and monofluoromethyl(4-nitrophenyl)sulfonium bis(carbomethoxy)methylide (3 b), and their reactions under mild conditions with a variety of nucleophiles, such as alcohols and malonate derivatives, sulfonic and carboxylic acids, phenols, amides, and N heteroarenes, are described. Mechanistic studies with deuterated reagents [D2]3 a/[D2]3 b suggest that these monofluoromethylation reactions proceed through an electrophilic substitution pathway.
- Liu, Yafei,Lu, Long,Shen, Qilong
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- METHOD FOR PREPARING FLUORINE-18-LABELED FLUOROMETHYL-SUBSTITUTED RADIOPHARMACEUTICALS USING SELECTIVE AZIDE SUBSTITUTION REACTION AND PRECURSOR SCAVENGING
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A method for preparing a fluorine-18-labeled fluoromethyl-substituted radiopharmaceutical using a selective azide substitution reaction includes (1) obtaining a [18F]fluoride from a cyclotron through an 18O(p,n)18F reactio
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Paragraph 0083-0085
(2021/07/10)
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- HPLC-free: In situ 18F-fluoromethylation of bioactive molecules by azidation and MTBD scavenging
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Sequential usage of azide and MTBD, which generates pure [18F]fluoromethyl tosylate and scavenges unreacted desmethyl precursors, provided an efficient HPLC-free strategy for the radiosynthesis of 18F-fluoromethylated compounds with
- Lu, Yingqing,Choi, Ji Young,Kim, Sang Eun,Lee, Byung Chul
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p. 11798 - 11801
(2019/10/02)
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- Investigation on the impact of three different quaternary methyl ammonium cartridges on the radiosynthetic yields of [18F]fluoromethyl tosylate
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Our recent investigations for the radiosynthesis of [18F]fluoromethyl tosylate have highlighted that choice of quaternary methyl ammonium (QMA) cartridge used during the radiosynthesis can significantly impact the radiochemical yields. Often the details of the QMA cartridge used in fluourine-18 syntheses are not fully described. However, our studies demonstrate that the type, the size, and nature (method by which it has been conditioned) of the QMA cartridge used during the radiosynthesis can make a significant impact in the labelling efficiency. This paper investigates the use of three QMA cartridges and demonstrates that radiochemical yield (decay corrected) of [18F]fluoromethyl tosylate can increase from 46% to 60% by simply changing the QMA cartridge (and leaving all other reagents and labelling conditions exactly the same). These learnings may be applied to improve the radiochemical yields of a number of [18F]-fluorinated tracers (and synthons), where the labelling step is base-sensitive to increase the radiochemical yield, thereby significantly benefiting the radiochemistry and nuclear medicine community. This paper also highlights the necessity of the radiochemistry community to ensure the details of QMA cartridges used in fluorine-18 chemistry are fully and accurately described, since this will improve the translation of radiochemical methods from one laboratory to another.
- Stimson, Damion H.R.,Qiao, Zheng,Reutens, David C.,Venkatachalam, Taracad K.,Bhalla, Rajiv
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p. 588 - 595
(2019/08/01)
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- 11C- and 18F-Labeled Radioligands for P-Glycoprotein Imaging by Positron Emission Tomography
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P-Glycoprotein (P-gp) is an efflux transporter widely expressed at the human blood-brain barrier. It is involved in xenobiotics efflux and in onset and progression of neurodegenerative disorders. For these reasons, there is great interest in the assessmen
- Cantore, Mariangela,Benadiba, Marcel,Elsinga, Philip H.,Kwizera, Chantal,Dierckx, Rudi A. J. O.,Colabufo, Nicola Antonio,Luurtsema, Gert
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p. 108 - 118
(2016/01/15)
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- Re-exploring the N-phenylpicolinamide derivatives to develop mGlu4 ligands with improved affinity and in vitro microsomal stability
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Abstract In recent years, mGlu4 has received great attention and research effort because of the potential benefits of mGlu4 activation in treating numerous brain disorders, such as Parkinson's disease (PD). Many positive allosteric m
- Zhang, Zhaoda,Kil, Kun-Eek,Poutiainen, Pekka,Choi, Ji-Kyung,Kang, Hye-Jin,Huang, Xi-Ping,Roth, Bryan L.,Brownell, Anna-Liisa
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p. 3956 - 3960
(2015/08/24)
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- ANTIBACTERIAL AGENTS: N(ALPHA)-AROYL-N-ARYL-PHENYLALANINAMIDES
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The invention provides compounds having activity as bacterial RNA polymerase inhibitors and antibacterial agents, as well as compositions comprising the compounds and methods for their use. Specifically, phenylalanineamide and tyrosinamide compounds are disclosed that have inhibitory activity toward mycobacterium tuberculosis RNA polymerase. Use of these compounds in the treatment o prevention of M. tuberculosis infections in a mammal, is disclosed.
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Page/Page column 89
(2015/09/22)
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- Fluorine-containing 6,7-dialkoxybiaryl-based inhibitors for phosphodiesterase 10 A: Synthesis and in vitro evaluation of inhibitory potency, selectivity, and metabolism
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Based on the potent phosphodiesterase 10 A (PDE10A) inhibitor PQ-10, we synthesized 32 derivatives to determine relationships between their molecular structure and binding properties. Their roles as potential positron emission tomography (PET) ligands were evaluated, as well as their inhibitory potency toward PDE10A and other PDEs, and their metabolic stability was determined in vitro. According to our findings, halo-alkyl substituents at position 2 of the quinazoline moiety and/or halo-alkyloxy substituents at positions 6 or 7 affect not only the compounds′ affinity, but also their selectivity toward PDE10A. As a result of substituting the methoxy group for a monofluoroethoxy or difluoroethoxy group at position 6 of the quinazoline ring, the selectivity for PDE10A over PDE3A increased. The same result was obtained by 6,7-difluoride substitution on the quinoxaline moiety. Finally, fluorinated compounds (R)-7-(fluoromethoxy)-6-methoxy-4-(3-(quinoxaline-2-yloxy)pyrrolidine-1-yl) quinazoline (16 a), 19 a-d, (R)-tert-butyl-3-(6-fluoroquinoxalin-2-yloxy) pyrrolidine-1-carboxylate (29), and 35 (IC50 PDE10A 11-65 nM) showed the highest inhibitory potential. Further, fluoroethoxy substitution at position 7 of the quinazoline ring improved metabolic stability over that of the lead structure PQ-10. Fluor your health: Phosphodiesterase 10 A (PDE10A) has emerged as an attractive target for the development of 18F-labelled brain imaging agents for positron emission tomography. A series of fluorinated dialkoxybiaryl compounds were synthesized and evaluated as PDE10A inhibitors, assisted by QSAR docking studies. The 7-fluoromethoxy derivative appears to be a promising candidate for further development.
- Schwan, Gregor,Barbar Asskar, Ghadir,Hoefgen, Norbert,Kubicova, Lenka,Funke, Uta,Egerland, Ute,Zahn, Michael,Nieber, Karen,Scheunemann, Matthias,Straeter, Norbert,Brust, Peter,Briel, Detlef
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p. 1476 - 1487
(2014/07/21)
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- 2-PYRIDYLOXY-4-ETHER OREXIN RECEPTOR ANTAGONISTS
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The present invention is directed to 2-pyridyloxy-4-ether compounds which are antagonists of orexin receptors. The present invention is also directed to uses of the 2-pyridyloxy-4-ether compounds described herein in the potential treatment or prevention o
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- ISOTOPIC CARBON CHOLINE ANALOGS
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Novel radiotracer(s) for Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging of disease states related to altered choline metabolism (e.g., tumor imaging of prostate, breast, brain, esophageal, ovarian, endomet
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Page/Page column 43
(2012/04/10)
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- NOVEL PRECURSOR
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Novel radiotracer(s) for Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging of disease states related to altered choline metabolism (e.g., tumor imaging of prostate, breast, brain, esophageal, ovarian, endomet
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- NOVEL RADIOTRACER
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Novel radiotracer(s) for Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging of disease states related to altered choline metabolism (e.g., tumor imaging of prostate, breast, brain, esophageal, ovarian, endomet
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- Inherent oxygen preference in enolate monofluoromethylation and a synthetic entry to monofluoromethyl ethers
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Expect the unexpected: The self-stable salts 1, X=OTf, PF6, x=2, y=1, developed for electrophilic monofluoromethylation showed inherent selectivity for the O-alkylation of enolates, thus providing access to monofluoromethyl ethers, which are difficult to obtain by the direct electrophilic fluoromethylation of alcohols. Salt 1, X=BF4, x=0, y=3, in contrast leads to C-alkylated products.
- Nomura, Yoshinori,Tokunaga, Etsuko,Shibata, Norio
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supporting information; experimental part
p. 1885 - 1889
(2011/04/22)
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- Improved synthesis of [18F]fluoromethyl tosylate, a convenient reagent for radiofluoromethylations
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The utility of [18F]fluoromethyl tosylate as an [ 18F]fluoromethylation reagent has been reexamined. The preparation of this potentially useful compound from the reaction of bis(tosyloxy) methane with 18F- was reported sev
- Neal, Timothy R.,Apana, Scott,Berridge, Marc S.
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p. 557 - 568
(2007/10/03)
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- Radiosynthesis of O-[11C]methyl-L-tyrosine and O-[18F]Fluoromethyl-L-tyrosine as potential PET tracers for imaging amino acid transport
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Two positron-emitting analogues of tyrosine, O-[11C]methyl-L-tyrosine and O- [18F]fluoromethyl-L-tyrosine were prepared as new tumor imaging agents. The alkylating agent, [11C]methyl triflate or [18F]fluoromethy
- Iwata, Ren,Furumoto, Shozo,Pascali, Claudio,Bogni, Anna,Ishiwata, Kiichi
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p. 555 - 566
(2007/10/03)
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