762-49-2Relevant academic research and scientific papers
Conformational stability, far-infrared spectra, barriers to internal rotation, vibrational assignment and RHF/STO-3G* calculations of 1-bromo-2-fluoroethane
Durig, J. R.,Liu, Jian,Little, T. S.
, p. 25 - 48 (1991)
The far-IR spectrum (350-35 cm-1) of gaseous 1-bromo-2-fluoroethane, BrCH2CH2F, has been recorded at a resolution of 0.10 cm-1.The fundamental asymmetric torsional frequencies of the more stable trans (two halogen atoms oriented trans) and high energy gauche conformers have been observed at 125.3 cm-1 and 111.3 cm-1, respectively, and the asymmetric torsional potential function governing internal rotation about the C-C bond has been determined.This potential function gives values for the torsional potential coefficients of V1= 584+/-6, V2=-147+/-4, V3=1217+/-11, V4=138+/-2, and V6=-21+/-4 cm-1, and a dihedral angle (FCCBr) of 67 deg for the gauche conformer.The trans to gauche, gauche to gauche, and gauche to trans barriers have been determined to be 1356 cm-1, 1418 cm-1 and 973 cm-1, rspectively, with an energy difference between the conformations of 383+/-21 cm-1 (1.09+/-0.06 kcal mol-1).From studies of the Raman spectra at variable temperatures the conformational energy difference has been determined to be 350+/-87 cm-1 (1.00+/-0.25 kcal mol-1) with the trans more stable and 300+/-46 cm-1 (0.86+/-0.13 kcal mol-1) with the gauche more stable for the gas and liquid, respectively.A complete assignment of the vibrational spectra including the IR (3500-400 cm-1) spectra of the gas and solid and the Raman (3200-10 cm-1) spectra of the gas, liquid and solid is proposed.The structural parameters, conformational stabilities, barriers to internal rotation and fundamental vibrational frequencies which have been determined from experiment, are compared to those obtained from ab initio Hartree-Fock gradient calculations and to the corresponding quantities obtained for some similar molecules.
Synthesis and radiopharmacological characterisation of a fluorine-18-labelled azadipeptide nitrile as a potential PET tracer for invivo imaging of cysteine cathepsins
Loeser, Reik,Bergmann, Ralf,Frizler, Maxim,Mosch, Birgit,Dombrowski, Lilli,Kuchar, Manuela,Steinbach, Joerg,Guetschow, Michael,Pietzsch, Jens
, p. 1330 - 1344 (2013/08/23)
A fluorinated cathepsin inhibitor based on the azadipeptide nitrile chemotype was prepared and selected for positron emission tomography (PET) tracer development owing to its high affinity for the oncologically relevant cathepsins L, S, K and B. Labelling with fluorine-18 was accomplished in an efficient and reliable two-step, one-pot radiosynthesis by using 2-[18F]fluoroethylnosylate as a prosthetic agent. The pharmacokinetic properties of the resulting radiotracer compound were studied invitro, exvivo and invivo in normal rats by radiometabolite analysis and small-animal positron emission tomography. These investigations revealed rapid conjugate formation of the tracer with glutathione in the blood, which is associated with slow blood clearance. The potential of the developed 18F-labelled probe to image tumour-associated cathepsin activity was investigated by dynamic small-animal PET imaging in nude mice bearing tumours derived from the human NCI-H292 lung carcinoma cell line. Computational analysis of the obtained image data indicated the time-dependent accumulation of the radiotracer in the tumours. The expression of the target enzymes in the tumours was confirmed by immunohistochemistry with specific antibodies. This indicates that azadipeptide nitriles have the potential to target thiol-dependent cathepsins invivo despite their disadvantageous pharmacokinetics.
COMPOUNDS AND COMPOSITIONS FOR THE DETECTION AND TREATMENT OF ALZHEIMER'S DISEASE AND RELATED DISORDERS
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Page/Page column 61, (2009/10/22)
One aspect of the present invention relates to compounds, compositions and methods for diagnosis and/or treatment of a subject suffering from an amyloidosis-associated pathological condition. In certain embodiments, the imaging and/or therapeutic agents of the instant invention may be administered to a subject for identification and/or treatment of amyloid deposits. A specific imaging method detects amyloid deposits by administering the imaging agent to the subject and detecting the spatial distribution of the agent. Differential accumulation of the agent is indicative of AD or an amyIoidosis-associated pathological condition and can be monitored by using a PET or SPECT camera.
Triazole derivatives
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, (2011/03/17)
The present invention relates to triazole and imidazole derivatives of formula I and to their pharmaceutically acceptable acid addition salts. These compounds are NMDA receptor subtype blockers and are useful for the treatment of diseases related to the NMDA receptor.
A Rapid and Efficient Method for the Fluoroalkylation of Amines and Amides. Development of a Method Suitable for Incorporation of the Short-Lived Positron Emitting Radionuclide Fluorine-18
Chi, Dae Yoon,Kilbourn, Michael R.,Katzenellenbogen, John A.,Welch, Michael J.
, p. 658 - 664 (2007/10/02)
We have described a two-step method for the preparation of fluoroalkyl-substituted amines and amides.The sequence involves fluoride ion displacement of a haloalkyl trifluoromethanesulfonate (triflate), followed by fluoroalkylation of the heteroatom system (amine or amide) by the fluoroalkyl halide.Alternatively, the fluoroalkyl halide can be prepared by halofluorination of a terminal olefin.These reactions have been used to prepare various fluoroalkyl derivatives of N-phenylpiperazine and N-fluoroalkyl derivatives of the neuroleptic agent spiperone (7).The sequence is rapid, convenient, and efficient, even when fluoride ion is the limiting reagent.Therefore, it is readily adaptable to the preparation of a variety of compounds labeled with the short half-life (t1/2 = 110 min) positron-emitting radionuclide fluorine-18.
NEW PENTAFLUOROTHIO(SF5)FLUOROPOLYMERS
Terjeson, Robin J.,Gard, Gary L.
, p. 653 - 662 (2007/10/02)
New fluorinated polymers containing the pentafluorothio group have been prepared from SF5Br and the appropriate fluoroolefin under reaction temperatures of 90+/-5 deg C and autogeneous pressures of up to 90 atmospheres for periods of four days to two weeks.With ethylene, FCH2CH2Br and SF5CH2CH2Br were formed.A new monomer addition product, SF5CF2CF2Br, is also reported for the first time.
REACTIONS OF CHLORINE MONOFLUORIDE. VI. RELATIVE RATES OF SUBSTITUTIVE FLUORINATION OF BROMINE-SUBSTITUTED ALKANES. HYDRIDE SHIFTS AND OTHER MIGRATIONS DURING FLUORINATION
Morozova, T. V.,Chuvatkin, N. N.,Panteleeva, I. Yu.,Boguslavskaya, L. S.
, p. 1255 - 1263 (2007/10/02)
The relative rates of substitutive fluorination of bromoalkanes with various structures by chlorine monofluoride in a nonpolar medium at 20-40 deg C were investigated by the method of competing reactions.Halogen atoms vicinal with the substituted bromine greatly reduce the fluorination rate.The reactivity of the secondary bromides decreases in the order (CH3)2CHBr>>CH3CHBrCH2Cl>>CH2ClCHBrCH2Cl.The geminal halogen atoms have little effect on the rate of substitutive fluorination.The fluorination rates of the bromoalkanes CH2BrCH2Br, CH2BrCHClBr, and CH2BrCCl2Br are in ratios 10:3:1 respectively, while the fluorination rate of CH3CHClBr is much higher than that of CH2ClCH2Br.As a rule the debromination of primary bromides containing vicinal halogens (Br, Cl) is accompanied by migration of the latter and gives fluorides with iso structures.Hydride shifts take place in cases where stable tertiary or secondary carbocations are formed as a result of migration of the hydride; for example, the fluorination of CH3CHFCH2Br leads to the geminal difluoroalkane CH3CF2CH3.The mechanism of substitutive fluorination is discussed.
On the Intermediary Existence of Gaseous Ethylen Fluoronium Ions
Ciommer, Bernhard,Schwarz, Helmut
, p. 635 - 638 (2007/10/02)
The long-sought ethylen fluoronium ion (2) is generated as an intermediate in the dissociative ionization of 1-fluoro-2-(p-methyl)phenoxy ethane (4).However, prior to collisionally induced dissociation 2 undergoes ring-opening, associated with hydrogen migration, to form 1-fluoroethyl cation (3).Other decomposition pathways of the molecular ions of 4 involve (i) direct formation of 3 via a combination of C-O cleavage (loss of ArO(*)) and hydrogen migration (18percent) and (ii) complete positional loss of the α- and β-methylene hydrogen atoms (34percent).The remaining 48percent of the m olecular ions of 4 dissociate via anchimeric assistance of the fluorine in the elimination of ArO(*), thus giving rise to the formation of 2. - Keywords: Fluoronium Ions, Neighbouring Group Participation, Gaseous Ions, Collisional Activation, Mass Spectrometry
