Kinetics and mechanism for oxime formation from 4-dimethylaminobenzaldehyde and 4-trimethylammoniobenzaldehyde iodide
摘要:
The following lines of evidence establish that oxime formation from 4-dimethylaminobenzaldehyde and 4-trimethylammoniobenzaldehyde iodide occurs with a simple two-step mechanism. The pH-rate profile for the reaction of 4-trimethylammoniobenzaldehyde iodide exhibits, in order of decreasing pH, a negative deviation at pH near 2.0, corresponding to a transition from rate-determining step carbinolamine dehydration with acid catalysis to the uncatalyzed carbinolamine formation. In the case of the reaction of 4-dimethylaminobenzaldehyde, the pH-profile exhibits, in order of decreasing pH, a positive deviation at pH near 3.5 and then a negative deviation at pH near 2.0. These deviations have been interpreted in terms of i) transition of the rate-determining step, and ii) protolytic equilibrium of the substrate. (C) 1999 John Wiley & Sons, Inc.
1-(4-[<sup>18</sup>F]Fluorobenzyl)-4-[(tetrahydrofuran-2-yl)methyl]piperazine: A Novel Suitable Radioligand with Low Lipophilicity for Imaging σ<sub>1</sub> Receptors in the Brain
corresponding radiotracer [18F]10 demonstrated high brain uptake and extremely high brain-to-blood ratios in biodistribution studies in mice. Pretreatment with the selective σ1 receptor agonist SA4503 significantly reduced the level of accumulation of the radiotracer in the brain. No radiometabolite of [18F]10 was observed to enter the brain. Positronemissiontomography and magnetic resonance imaging confirmed
Radiolabeled pyridinyl analogues of dibenzylideneacetone as β-amyloid imaging probes
作者:Xiaomei Cui、Xiaoyang Zhang、Cheng Peng、Jiapei Dai、Boli Liu、Mengchao Cui
DOI:10.1039/c6ra05168e
日期:——
In continuation of our investigation of the dibenzylideneacetone scaffold as Aβ imaging probes, a series of derivatives containing pyridine rings with lower lipophilicity was synthesized and evaluated.
SYNTHESIZING PET TRACERS USING [F-18]SULFONYL FLUORIDE AS A SOURCE OF [F-18]FLUORIDE
申请人:Zhou Dong
公开号:US20170197912A1
公开(公告)日:2017-07-13
The present disclosure relates to the methods for the preparation of reactive [F-18]fluoride in a form of [F-18]sulfonyl fluoride suitable for efficient radiolabeling without an azeotropic evaporation step by the use of anion exchange resin and sulfonyl chloride, and its applications in the manufacturing of PET radiopharmaceuticals.