24313-53-9Relevant articles and documents
Chronobiotic activity of N-[2-(2,7-dimethoxyfluoren-9-yl)ethyl]- propanamide. Synthesis and melatonergic pharmacology of fluoren-9-ylethyl amides
Epperson, James R.,Bruce, Marc A.,Catt, John D.,Deskus, Jeffrey A.,Hodges, Donald B.,Karageorge, George N.,Keavy, Daniel J.,Mahle, Cathy D.,Mattson, Ronald J.,Ortiz, Astrid A.,Parker, Michael F.,Takaki, Katherine S.,Watson, Brett T.,Yevich, Joseph P.
, p. 4601 - 4611 (2004)
Compound 2b demonstrated full agonism at both human MT1 and MT2 receptors and demonstrated chronobiotic activity in both acute and chronic rat models, producing an acute phase advance of 32 min at 1 mg/kg and chronically entraining free-running rats with a mean effective dose of 0.23 mg/kg. This compound was significantly less efficacious than melatonin in constricting human coronary artery. A series of fluoren-9-yl ethyl amides (2) were synthesized and evaluated for human melatonin MT1 and MT 2 receptor binding. N-[2-(2,7-dimethoxyfluoren-9-yl)ethyl]propanamide (2b) was selected and evaluated in functional assays measuring intrinsic activity at the human MT1 and MT2 receptors and demonstrated full agonism at both receptors. The chronobiotic properties of 2b were demonstrated in both acute and chronic rat models where 2b produced an acute phase advance of 32 min at 1 mg/kg and chronically entrained free-running rats with a mean effective dose of 0.23 mg/kg. Compound 2b is significantly less efficacious than melatonin in constricting human coronary artery.
Cross dehydrogenative coupling via base-promoted homolytic aromatic substitution (BHAS): Synthesis of fluorenones and xanthones
Wertz, Sebastian,Leifert, Dirk,Studer, Armido
, p. 928 - 931 (2013/03/28)
Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant. Initiation of the radical chain reaction is best achieved with small amounts of FeCp2 (0.1 or 1 mol %).
The mechanisms of long-range 13C, 19F and 19F,19F coupling constants in derivatives of biphenyl and fluorene. Differential isotope shifts.
Schaefer, Ted,Peeling, James,Penner, Glenn H.
, p. 2162 - 2167 (2007/10/02)
13C, 19F and 19F, 19F nuclear spin-spin coupling constants over formal bonds, n = 1-9, are reported for 4-fluorobiphenyl, 4,4'-difluorobiphenyl, 4,4'-difluoro-2,2',6,6'-tetramethylbiphenyl, 2,7-difluorofluorene, 2-fluoro-9-fluorenone, and 2,7-difluoro-9-fluorene in acetone solutions.The signs of many of the coupling constants are deduced from second-order spectral phenomena caused by differential 13C isotope effects on the 19F nmr chemical shifts.Theoretical potentials, based on geometry-optimized STQ 3G MO computations for 4-fluorobiphenyl and 4,4'-difluorobiphenyl, yield expectation values for the torsion angles about the exocyclic C-C linkage that are very close to those deduced from electron diffraction patterns.These potentials and INDO MO FPT computations of the long-range constants allow a discussion of the coupling mechanisms.In Hz, 9J(F,F) = 1.3(1) cos2 Θ, where Θ is zero for a planar biphenyl, while 8J(C,F) = 0.8(1) cos2 Θ and 7J(C,F) = -0.43(5) cos2Θ. 6J(C,F) is a composite of ?-? and ? electron coupling components and is written in Hz as 0.57(1) + 0.29(1) sin2Θ.The corresponding coupling constants in the fluorene and 9-fluorene derivatives are enhanced in magnitude relative to a hypotheoretical planar biphenyl derivative.It is tentatively suggested that 5J(C,F) consist of three coupling components, one negative and proportional to cos2, the other two positive and independent of Θ. 4J(C,F) is suggested to consist of a ? component of -1.0 Hz and a ? component proportional to the atom-atom polarizability for hte parent hydrocarbon.
