The synthesis of new diastereomers of (4S,8aS)- and (4R,8aS)-4-phenyl-perhydropyrrole[1,2-a]pyrazine-1,3-dione
摘要:
The synthesis of new (4S,8aS)- and (4R,8aS)-4-phenyl-perhydropyrrole[1,2-a]pyrazine-1,3-diones in the cyclocondensation reaction of the respective derivatives of L-prolineamide is described. The effect of the amount of NaOEt, temperature, and reaction time on the proportions of diastereomers formed in the cyclocondensation reaction was examined. The structures of the diastercomers were confirmed by GC/MS, FIRMS, HPLC; XRD, and H-1 and C-13 NMR investigations. (C) 2007 Elsevier Ltd. All rights reserved.
A number of novel pyrrole[1,2-a]pyrazinederivatives were synthesized and evaluated in in vivo animal models of epilepsy. Among them, several compounds displayed promising seizure protection in the maximal electroshock seizure (MES), subcutaneous metrazol seizure (scMET), 6 Hz and pilocarpine-induced status prevention (PISP) tests, with ED50 values comparable to the reference anticonvulsant drugs (AEDs)
合成了许多新颖的吡咯[1,2- a ]吡嗪衍生物,并在癫痫的体内动物模型中进行了评估。其中,几种化合物在最大电击惊厥(MES),皮下甲硝唑惊厥(scMET),6 Hz和毛果芸香碱引起的状态预防(PISP)测试中显示出有希望的癫痫保护作用,其ED 50值可与参考抗惊厥药(AEDs)相提并论。 )。观察到吡咯[1,2- a ]吡嗪核心的立体化学和构象偏好对体内药理活性的关键影响。合成药物的抗惊厥作用机制很可能不是通过抑制电压依赖性钠(Na+)电流。
The synthesis and conformational analysis of optical isomers of 4-phenyl-perhydropyrido[1,2-a]pyrazine-1,3-dione: an example of ‘solid state–frozen’ dynamics in nitrogen-bridged bicyclic 2,6-diketopiperazines
The synthesis, chemical properties, and conformational analysis of enantiopure (4R,9aS)-, (4S,9aR)-, (4S,9aS)-, and (4R,9aR)-4-phenyl-perhydropyrido[1,2-a]pyrazine-1,3-diones having potential biological activity are described. An interesting example of the coexistence of two invertomers of the (4R,9aR)-diastereomer in a single crystal unit cell is reported. The invertomers differ in the cis/trans-relationship between the fused rings and in the absolute configuration at the chiral nitrogen atom. The structure and equilibrium distributions of the respective conformers have been determined by NMR spectroscopy in both polar and non-polar solvents at various temperatures. The NMR spectra show that dynamic processes in the imide parts of the interconverting species are restrained by self-aggregation. The (4S,9aR)-diastereomer exists in a single conformation with insignificant dynamic effects. (c) 2009 Elsevier Ltd. All rights reserved.