1,2-Fused pyrimidines VII. 3-(Dialkylamino)-1H-pyrimido[1,2-a]quinolin-1-ones and 2-(dialkylamino)-4H-pyrimido[2,1-a]isoquinolin-4-ones as antiplatelet compounds
摘要:
A number of 3-(dialkylamino)-1H-pyrimido[1,2-a]quinolin-1 ones 3 and 2-(dialkylamino)-4H-pyrimido [2,1-a]isoquinolin-4-ones 4 were prepared by treating the corresponding chloro derivatives with an excess of dialkylamines. The highest in vitro antiplatelet activity was obtained when the dialkylamino substituent was 1-piperazinyl (compounds 3g and 4e). The novel 2-(1-piperazinyl)-4H-pyrido[ ,2-a]pyrimidin-4-one 2a was also prepared by an analogous procedure, which resulted in the most active compound towards all the platelet aggregation inducers used (ADP, collagen, A 23187). Moreover, some examples of 1-(dialkylamino)-3H pyrimido[l,2-a]quinolin-3-ones 5 and 4-(dialkylamino)-2H-pyrimido[2,1-a]isoquinolin-2-ones 6 were also obtained (together with negligible or lower amounts of the corresponding isomers 3 and 4, respectively) from the cyclocondensation of the appropriate ethyl N,N-dialkylmalonamate/phosphorus oxychloride reagents 13 with 2-aminoquinoline or 1-aminoisoquinoline. These;latter compounds showed a rather low antiplatelet activity.
A C=O⋅⋅⋅Isothiouronium Interaction Dictates Enantiodiscrimination in Acylative Kinetic Resolutions of Tertiary Heterocyclic Alcohols
作者:Mark D. Greenhalgh、Samuel M. Smith、Daniel M. Walden、James E. Taylor、Zamira Brice、Emily R. T. Robinson、Charlene Fallan、David B. Cordes、Alexandra M. Z. Slawin、H. Camille Richardson、Markas A. Grove、Paul Ha‐Yeon Cheong、Andrew D. Smith
DOI:10.1002/anie.201712456
日期:2018.3.12
C=O⋅⋅⋅isothiouronium interaction as key to efficient enantiodiscrimination in the kineticresolution of tertiary heterocyclic alcohols bearing up to three potential recognition motifs at the stereogenic tertiary carbinol center. This discrimination was exploited in the isothiourea‐catalyzed acylative kineticresolution of tertiary heterocyclic alcohols (38 examples, s factors up to >200). The reaction proceeds at low
Malonamate, malonic acid and malonamide derivatives of heterocyclic compounds were synthesized as part of a search for new biologically active compounds, e. g., those having antiinflammatory activity. Malonamates (1-17) were prepared by the reaction of amines containing heterocycles with malonic acid monoethyl ester. Hydrolysis of the malonamates gave the malonamic acids (18-24) in good yields. Malonamides (25-43) were synthesized by condensing amines with N-substituted malonamic acids. The antiinflammatory activity of these compounds was examined against carrageenin-induced rat paw edema. N-[2-(6-Methoxy) benzothiazolyl] malonamic acid (23) and its ethyl ester (7) showed significant activity.
作者:Kui Wang、Yi-Shi Wu、Gui-Tao Wang、Ren-Xiao Wang、Xi-Kui Jiang、Hong-Bing Fu、Zhan-Ting Li
DOI:10.1016/j.tet.2009.06.087
日期:2009.9
chloroform indicate that such a structural matching remarkably facilitates the intramolecular energy and electron transfer and charge separation between the two chromophores and also retards the recombination of the charge-separated state. Removing one hydrogen bond considerably reduces the energy and electron transfer. Further removing another one leads to no important interaction between the chromophores
通过共价连接发色团在氢键芳基酰胺衍生的折叠架桥的相对端,已经合成了四个卟啉桥-C 60二联体。为了比较,还制备了相同构架的四种不含C 60的卟啉衍生物。完全氢键连接的桥使连接的卟啉和C 60部分以面对面的方式接触。1个在氯仿中的1 H NMR,UV-vis和荧光研究表明,这种结构匹配显着促进了两个发色团之间的分子内能量和电子转移以及电荷分离,并且还阻碍了电荷分离状态的重组。除去一个氢键会大大减少能量和电子转移。进一步除去另一种不会导致生色团之间发生重要的相互作用。
Synthesis, in vitro antiplatelet activity and molecular modelling studies of 10-substituted 2-(1-piperazinyl)pyrimido[1,2- a ]benzimidazol-4(10 H )-ones
The multistep preparation of the new 10-substituted 2-(1-piperazinyl)pyrimido[1,2-a]benzimidazol-4(10H)-ones 6a-o, and of the two isomers 10-ethyl-2-(diethylamino)pyrimido[1,2-a]benzimidazol-4(10H)-one 6p and 10-ethyl-4-(diethylamino)pyrimido[1,2-a]benzimidazol-2(10H)-one 13, as well as the in vitro evaluation of their inhibitory activity on human platelet aggregation induced in platelet-rich plasma by ADP, collagen or the Ca2+ ionophore A23187 were here described. Nine out of fifteen 2-(1-piperazinyl)derivatives (6g-o) showed good inhibitory properties towards all the platelet aggregation agonists used. Moreover, a molecular modelling study has been performed on two of the best compounds of this series (6i and 6o) to confirm in silico their interactions with the catalytic site of human platelet PDE3, using the X-ray data of the PDE3B isoform in complex with an inhibitor. (C) 2013 Elsevier Masson SAS. All rights reserved.
Foldamer-based pyridine–fullerene tweezer receptors for enhanced binding of zinc porphyrin
作者:Zong-Quan Wu、Chang-Zhi Li、Dai-Jun Feng、Xi-Kui Jiang、Zhan-Ting Li
DOI:10.1016/j.tet.2006.09.046
日期:2006.11
This paper reports the design and synthesis of a new series of hydrogen bonding-mediated foldamer-derived tweezer receptors that are used for efficient complexation of zinc porphyrin guest. One end of the rigidified aromatic amide backbone is incorporated with one fullerene unit, while another end is connected to one pyridine or imidazole unit. The H-1 NMR, UV-vis, and fluorescent investigations in chloroform revealed that, due to the intramolecular hydrogen bonding-driven preorganized folded conformation, the fullerene and pyridine units of the receptors are located with suitable spatial separation and consequently able to co-complex zinc porphyrin with remarkably increased stability. In contrast, the imidazole-incorporated receptor displays a weakened binding affinity possibly due to structural mismatching and large steric hindrance. The association constants of the complexes of the new receptors with zinc porphyrin have been determined. (c) 2006 Elsevier Ltd. All rights reserved.