Antimalarial drugs. 60. Synthesis, antimalarial activity, and quantitative structure-activity relationships of tebuquine and a series of related 5-[(7-chloro-4-quinolinyl)amino]-3-[(alkylamino)methyl][1,1'-biphenyl]-2-ols and N.omega.-oxides
摘要:
A series of 5-[(7-chloro-4-quinolinyl)amino]-3-[(alkylamino)methyl] [1,1'-biphenyl]-2-ols and N omega-oxides was prepared from the substituted 1-phenyl-2-propanones proceeding through the 5-nitro[1,1'-biphenyl]-2-ols, the corresponding amino, and acetamido derivatives to the N-[5-[(alkylamino)methyl]-6-hydroxy[1,1'-biphenyl]-3-yl]acetamides and final condensation with 4,7-dichloroquinoline or the N-oxide. In a quantitative structure-activity relationship study first run on 28 and later expanded to 40 substituted phenyl analogues and their N omega-oxides, increasing antimalarial potency vs. Plasmodium berghei in mice was found to be correlated with decreasing size (sigma MR) and electron donation (sigma sigma) of the phenyl ring substituents. A significant correlation with N omega-oxidation could not be demonstrated. Initial high activity against P. berghei infections in mice led to expanded studies that demonstrated in addition excellent activity against resistant strains of parasite, activity in primate models, and pharmacokinetic properties apparently allowing protection against infection for extended periods of time even after oral administration. Such properties encourage the clinical trial of a member of this class in man.
Phenoxenium ions identical intermediates in the acid-catalyzed solvolysis of n-tosyl-O-Arylhydroxylamines and in the thermolysis of N-Aryloxypyridinium salts
The acid-catalyzed solvolysis of N-tosyl-O-arylhydroxylamines in aromatic solvents and the thermolysis of N-arylqxypyridinium salts involve common intermediates, phenoxenium ions, for the formation of hydroxybiphenyl derivatives. Diphenylethers are formed when the hydrolysis of the N—O bonds is slow and the aromatic solvent has high nucleophilicity.
Thyroid hormone analogs. Synthesis of 3'-substituted 3,5-diiodo-L-thyronines and quantitative structure-activity studies of in vitro and in vivo thyromimetic activities in rat liver and heart
作者:Paul D. Leeson、David Ellis、John C. Emmett、Virendra P. Shah、Graham A. Showell、Anthony H. Underwood
DOI:10.1021/jm00396a008
日期:1988.1
Twenty-nine novel 3'-substituted derivatives of the thyroid hormone 3,3',5-triiodo-L-thyronine (T3) have been synthesized by using established methods and by a new route involving manipulation of a 3'-formyl intermediate. In vitro hormone receptor binding (to intact nuclei) and in vivo thyromimetic activity (induction of mitochondrial 3-phosphoglycerate oxidoreductase, GPDH) were measured in rat liver and heart for these new analogues and for the 18 previously reported 3'-substituted 3,5-diiodo-L-thyronines. Analysis of the binding data using theoretical conformational and quantitative structure-affinity methods implies that the 3'-substituent recognition site on the thyroid hormone receptor is hydrophobic and limited in depth to the length of the natural iodo substituent, but has sufficient width to accommodate a phenyl or cyclohexyl group. Receptor binding is reduced by approximately 10-fold in 3'-acyl derivatives which form strong intramolecular acceptor hydrogen bonds with the adjacent 4'-hydroxyl. The compounds studied showed no differences in their relative affinities for heart and liver nuclei, suggesting that receptors in these tissues are similar. However, the relationships between thyromimetic activity (induction of GPDH) and nuclear binding showed some tissue differences. A high correlation between activity and binding is observed for full agonists in the heart, but an equally significant correlation for the liver data is only seen when 3'-substituent bulk (molar refractivity) is included in the analysis. These results suggest the possibility that differential tissue penetration or access to receptors may occur in vivo.
CuI-Mediated Sequential Iodination/Cycloetherification of <i>o</i>-Arylphenols: Synthesis of 2- or 4-Iododibenzofurans and Mechanistic Studies
An efficient synthesis of 2- or 4-iododibenzofurans through Cul-mediated sequential iodination/cycloetherification of two aromatic C-H bonds in o-arylphenols has been developed. Both the preexisting electron-withdrawing groups (NO2, CN, and CHO) and the newly introduced iodide are readily modified for a focused dibenzofuran library synthesis. Mechanistic studies and DFT calculations suggest that a Cu(III)-mediated rate-limiting C-H activation step is involved in cycloetherification.
Cu-Catalyzed Oxidative C(sp<sup>2</sup>)–H Cycloetherification of <i>o</i>-Arylphenols for the Preparation of Dibenzofurans
A new process involving copper-catalyzed aerobic C(sp(2))-H activation, followed by cycloetherification, has been developed. This reaction serves as a direct method for the preparation of multisubstituted dibenzofurans starting with o-arylphenols. The presence of a strong para-electron-withdrawing group (e.g., NO2) on the phenol is essential for the success of the reaction.
New non peptidic C5a receptor antagonists
作者:Peter C. Astles、Thomas J. Brown、Paul Cox、Frank Halley、Peter M. Lockey、Clive McCarthy、Iain M. McLay、Tahir N. Majid、Andrew D. Morley、Barry Porter、Andrew J. Ratcliffe、Roger J.A. Walsh
DOI:10.1016/s0960-894x(97)00124-8
日期:1997.1
A series of phenylguanidines which bind to the C5a receptor has been developed. The lead compound 1 (IC50=30 mu M), discovered through random screening, has been modified to provide 32 (RPR121154) with submicromolar activity. This compound was shown to further elicit functional antagonism in a human neutrophil C5a stimulated respiratory burst assay. (C) 1997 Elsevier Science Ltd.