4-(Tetrazolylalkyl)piperidine-2-carboxylic acids. Potent and selective N-methyl-D-aspartic acid receptor antagonists with a short duration of action
摘要:
We have prepared a series of cis-4-(tetrazolylalkyl)piperidine-2-carboxylic acids as potent and selective N-methyl-D-aspartic acid (NMDA) receptor antagonists. NMDA antagonists may prove to be useful therapeutic agents, for instance, as anticonvulsants, in the treatment of neurodegenerative disorders such as Alzheimer's disease and in the prevention of neuronal damage that occurs during cerebral ischemia. The compounds prepared were evaluated in vitro in both receptor binding assays ([H-3]CGS-19755, [H-3]AMPA, and [H-3]kainic acid) and in a cortical-wedge preparation (versus NMDA, quisqualic acid, and kainic acid) to determine affinity, potency, and selectivity. The new amino acids were also evaluated in vivo for their ability to block NMDA-induced convulsions in neonatal rats and NMDA-induced lethality in mice. The most potent compound of this series, 15 (LY233053), selectively displaced [H-3]CGS-19755 binding with an IC50 of 107 +/- 7 nM and selectively antagonized responses due to NMDA in a cortical-wedge preparation with an IC50 of 4.2 +/- 0.4-mu-M. Compound 15 blocked both NMDA-induced convulsions in neonatal rats (minimum effective dose (MED) = 20 mg/kg ip) and NMDA-induced lethality in mice (MED = 5 mg/kg ip). This is the first example of an NMDA receptor antagonist that incorporates a tetrazole moiety as an omega-acid bioisostere. These amino acid antagonists are also unique from their phosphonic acid counterparts in that they have a shorter duration of action in vivo. For the treatment of acute disorders such as stroke, where an NMDA antagonist would be administered parenterally, the shorter duration of action may be beneficial, e.g., allowing for better dosage control. The combination of potent NMDA receptor antagonism and a short duration of action may make these compounds useful therapeutic agents in the treatment of a variety of neurological disorders.
Direct Methenylation of 4-Alkylpyridines Using Eschenmoser’s Salt
作者:F. Christopher Pigge、Grant N. Shivers、Soe L. Tun、Shay L. McLean
DOI:10.1055/a-1916-5335
日期:2022.12
4-Alkylpyridines are converted into conjugated 1,1-disubstituted alkenyl pyridines (vinyl pyridines) upon treatment with excess ethyl chloroformate, triethylamine, and Eschenmoser’s salt. The reaction proceeds under mild conditions via alkylidene dihydropyridine intermediates.
Palladium-catalyzed allylation of 2- and 4-alkylpyridines via N-allyl alkylidene dihydropyridine intermediates
作者:Grant N. Shivers、F. Christopher Pigge
DOI:10.1016/j.tetlet.2023.154701
日期:2023.9
introduce allyl or cinnamyl groups to the picolyl positions of 2- or 4-alkylpyridines is described. Substituted N-allyl pyridinium salts are first treated with base (KOtBu) followed by catalytic [(η3-allyl)PdCl]2 and PPh3 to result in formal Pd-catalyzed transfer of N-allyl groups to the pyridine periphery. The reaction is believed to proceed through initial formation of nucleophilic alkylidene dihydropyridine
描述了将烯丙基或肉桂基引入2-或4-烷基吡啶的吡啶甲基位置的方法。首先用碱(KO t Bu)处理取代的N-烯丙基吡啶鎓盐,然后用催化[(η 3 -烯丙基)PdCl] 2和PPh 3处理,以导致N-烯丙基正式Pd催化转移到吡啶外围。据信该反应通过最初形成亲核亚烷基二氢吡啶中间体进行,该中间体与(π-烯丙基)Pd(II)亲电子试剂反应,从而再生N-烯丙基吡啶鎓阳离子。然后通过将 Pd(0) 氧化加成到这些活化的烯丙基上来实现催化转化和吡啶产物的释放。
ORNSTEIN, PAUL L.;SCHOEPP, DARRYLE D.;ARNOLD, M. BRIAN;LEANDER, J. DAVID;+, J. MED. CHEM., 34,(1991) N, C. 90-97
作者:ORNSTEIN, PAUL L.、SCHOEPP, DARRYLE D.、ARNOLD, M. BRIAN、LEANDER, J. DAVID、+