- Polyfluoroaralkylamines: an improved synthesis of 4,5,6,7-tetrafluoroindole
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Tetrafluoroindole (5), a precursor for potential biologically-active compounds, was prepared previously in a four-step synthesis from C6F6.However, catalytic reduction of pentafluorophenylacetonitrile (2) to 2-pentafluorophenylethyl amine (3) is accompanied by a significant amount of a secondary amine, which, like 3, undergoes cyclization to an indoline and subsequent dehydrogenation to a new indole 8.The side-reaction in the reduction of 2 to 3 is obviated by the use of LiAlH4/AlCl3 (1:1).The final aromatization to yield 5 is vastly improved by replacing MnO2 with DDQ. - Keywords: Polyfluoroaralkylamines; Synthesis; Tetrafluoroindole; NMR spectroscopy; IR spectroscopy
- Filler, Robert,Chen, Wei,Woods, Sarah M.
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- The synthesis of 7,8,9,10-Tetrafluoroellipticine
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We have synthesized a novel ellipticine analogue, 7,8,9,10-Tetrafluoroellipticine, in nine steps from hexafluorobenzene and ethyl cyanoacetate, via 1-(phenysulfonyl)-4,5,6,7-Tetrafluoroindole. The key step is lithiation of the indole and subsequent coupling with 3,4-pyridinedicarboxylic acid anhydride to afford a ketolactam. Reaction of the lactam with methyllithium followed by reduction with sodium borohydride yields 7,8,9,10-Tetrafluoroellipticine. formula presented.
- James Gruver,Onyango, Evans O.,Gribble, Gordon W.
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- Development of 3-(4-Chlorophenyl)-1-(phenethyl)urea Analogues as Allosteric Modulators of the Cannabinoid Type-1 Receptor: RTICBM-189 is Brain Penetrant and Attenuates Reinstatement of Cocaine-Seeking Behavior
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We have shown that CB1 receptor negative allosteric modulators (NAMs) attenuated the reinstatement of cocaine-seeking behaviors in rats. In an effort to further define the structure-activity relationships and assess the druglike properties of the 3-(4-chlorophenyl)-1-(phenethyl)urea-based CB1 NAMs that we recently reported, we introduced substituents of different electronic properties and sizes to the phenethyl group and evaluated their potency in CB1 calcium mobilization, cAMP, and GTPγS assays. We found that 3-position substitutions such as Cl, F, and Me afforded enhanced CB1 potency, whereas 4-position analogues were generally less potent. The 3-chloro analogue (31, RTICBM-189) showed no activity at >50 protein targets and excellent brain permeation but relatively low metabolic stability in rat liver microsomes. Pharmacokinetic studies in rats confirmed the excellent brain exposure of 31 with a brain/plasma ratio Kp of 2.0. Importantly, intraperitoneal administration of 31 significantly and selectively attenuated the reinstatement of the cocaine-seeking behavior in rats without affecting locomotion.
- Barrus, Daniel,Decker, Ann M.,Finlay, David B.,Gamage, Thomas F.,Glass, Michelle,Kenakin, Terry P.,Langston, Tiffany L.,Li, Jun-Xu,Nguyen, Thuy,Zhang, Yanan
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- Controlling the position of anions relative to a pentafluorophenyl group
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The position of an anion above an electron-deficient arene can be controlled by the geometry of appended directing groups. Here a series of ammonium substituted pentafluorophenyl derivatives is investigated. The presented results are one step on the way to find the ideal structural features for an effective and superior receptor for anion-π studies.
- Giese, Michael,Albrecht, Markus,Wiemer, Katharina,Valkonen, Arto,Rissanen, Kari
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p. 1368 - 1372
(2012/11/07)
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- N,N'-BIS(FLUOROPHENYLALKYL)-SUBSTITUTED PERYLENE-3,4:9,10-TETRACARBOXIMIDES, AND THE PREPARATION AND USE THEREOF
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The present invention relates to N,N'-bis(fluorophenylalkyl)-substituted perylene- 3,4:9,10-tetracarboximides, their preparation and their use as charge transport materials, exciton transport materials or emitter materials formula (I).
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Page/Page column 24
(2009/10/22)
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- N,N'-BIS(FLUOROPHENYLALKYL)-SUBSTITUTED PERYLENE-3,4:9,10-TETRACARBOXIMIDES, AND THE PREPARATION AND USE THEREOF
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The present invention relates to N,N′-bis(fluorophenylalkyl)-substituted perylene-3,4:9,10-tetracarboximides, their preparation and their use as charge transport materials, exciton transport materials or emitter materials.
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- Design and synthesis of N-nonpolar nucleobase dipeptides: Application of the Ugi reaction for the preparation of dipeptides havingfluoroarylalkyl groups appended to the nitrogen atom
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A single-step one-pot synthesis based on the Ugi four-component condensation of previously unknown dipeptides, 2,3,4 and 5, having afluoroaromatic group appended to the nitrogen atom, is described. The series of dipeptides produced here can be viewed as nonpolar nucleobase dipeptides since the difluorotoluene nucleoside 1 is a well known nonpolar analogue of natural thymidine. A mixture of N-protected amino acids 7, fluorophenethylamines 6, isocyanides 8, and acetone or paraformaldehyde are stirred in methanol in the presence of 3 A molecular sieves to furnish the N-fluoroarylethyl-Aib- or -Gly-containing dipeptides 2 or 3, in moderate yields. The dipeptides 2d and 3b, having a cyclohex-1-enamide moiety, are deprotected readily with 3 M HCl in THF to a3ord the free dipeptides in high yields. The N-fluoroarylmethyl-Aib- or -Gly-containingβ-alanyl dipeptides 4 or 5, designed based on the structure of 2′,5′-linked isoDNA, are also synthesized in a similar fashion to the preparation of 2, in moderate to good yields as both protected and free dipeptides.
- Das, Biplab Kumar,Shibata, Norio,Takeuchi, Yoshio
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p. 197 - 206
(2007/10/03)
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