Substituent effect on the reverse Menschutkin reaction of 1-methylpyridinium cations with iodide anion can be described in terms of the LArSR equation with ϱ=3.60 which provides evidence against very late transition state of the nitrogen-to-iodine transmethylation.
Excellent correlation between substituent constants and pyridinium N-methyl chemical shifts
作者:Sha Huang、Jesse C.S. Wong、Adam K.C. Leung、Yee Man Chan、Lili Wong、Myrien R. Fernendez、Amanda K. Miller、Weiming Wu
DOI:10.1016/j.tetlet.2009.06.081
日期:2009.9
Substituents on the pyridinium ring of N-methylpyridinium derivatives, especially those on the 2- or 4-position, have a large effect on the 1H and 13C NMR chemical shifts of the N-methyl group. Reasonable correlations between the chemical shift changes and the resonance substituentconstants are observed. The dual substituent parameter approach provides an excellent correlation when a combination of
Acetylcholinesterase inhibitors are currently of high interest due to the many reasons. Among them, Alzheimers disease drugs are of great interest. In this study, eleven monoquaternary pyridinium salts substituted by different groups (electron donors and electron acceptors) in position four were prepared. Then, their anticholinesterase activity was tested. As observed, their IC50s ranged from 33 μM to 3981 μM. Moreover, probability of blood-brain barrier penetration was predicted.
[EN] NOVEL PROCESS FOR PREPARING CEFTAROLINE FOSAMIL<br/>[FR] NOUVEAU PROCÉDÉ DE PRÉPARATION DE LA CEFTAROLINE FOSAMIL
申请人:SANDOZ AG
公开号:WO2013034718A1
公开(公告)日:2013-03-14
The present invention relates to a novel process for preparing ceftaroline fosamil as well as to a intermediates of formulae (1), (3) or (4) of this process.
Concise, enantiospecific synthesis of (3S,4R)-3-amino-4-ethylpiperidine as partner to a non-fluoroquinolone nucleus
作者:Michael Reilly、Donald R. Anthony、Corey Gallagher
DOI:10.1016/s0040-4039(03)00421-0
日期:2003.3
An enantiospecific, eight-step synthesis of (3S,4R)-3-amino-4-ethylpiperidine 3 starting from readily available (S)-(−)-α-methyl-4-pyridinemethanol 6 has been achieved utilizing an Overman rearrangement of a chiral allylic trichloroacetimidate 13 as the key step. A diastereoselective hydrogenation of the resulting chiral allylic amine 15 afforded predominantly the desired trans-substituted piperidine