There is provided amino acid derivatives of formula I,
wherein p, q, R1, R2, R3, R4, Y, n and B have meanings given in the description which are useful as competitive inhibitors of trypsin-like proteases, such as thrombin, and in particular in the treatment of conditions where inhibition of thrombin is required (e.g. thrombosis) or as anticoagulants.
A series of novel derivatives of artemisinin-4-(arylamino)quinazoline have been designed and synthesized, and most of them showing potent in vitro cytotoxic activityagainst HCT116 and WM-266-4 cell lines. Compound 32 was the most active derivative against HCT116 cell line with an IC50 of 110 nM, and significantly improved the antitumor activity of the parent compounds dihydroartemisinin (DHA) (IC50 = 2
Synthesis of 4-Quinolones via Cyclocondensation of Substituted ortho-Amidoacetophenones: A Refit to the Camps Cyclization by Applying Trimethylsilyl Trifluoromethanesulfonate/Triethylamine
A modification of the classical Camps cyclization is described. A series of substituted 4-quinolone derivatives is prepared via trimethylsilyl trifluoromethanesulfonate/triethylamine induced cyclocondensation of substituted ortho-amidoacetophenones. The process shows a broad substrate scope and allows selective preparation of 2-aryl- and 2-alkyl-substituted 4-quinolones. Enantiopure starting materials react without loss of optical purity using the modified conditions. Subsequent transformations of the products involving preparation of a 4-quinolyl nonaflate and O-selective methylation are also described.
A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction
作者:Christian Eidamshaus、Roopender Kumar、Mrinal K Bera、Hans-Ulrich Reissig
DOI:10.3762/bjoc.7.108
日期:——
reaction of alkoxyallenes, nitriles and carboxylicacids to provide beta-methoxy-beta-ketoenamides which are transformed into 4-hydroxypyridines in a subsequent cyclocondensation. The process shows broad substrate scope and leads to differentially substituted enantiopure pyridines in good to moderate yields. The preparation of diverse substituted lactic acid derived pyrid-4-yl nonaflates is described
An Efficient Protocol for Selective Silylation of Hydroxy Group Using <i>N</i>,<i>O</i>-Bis(<i>tert</i>-butyldimethylsilyl)acetamide and <i>N</i>,<i>N</i>-Dimethyl-4-aminopyridine <i>N</i>-Oxide
作者:Hiroki Mandai、Yuichiro Matsuura、Fatin Mahfuzah Binti Johari、Koichi Mitsudo、Seiji Suga
DOI:10.1246/cl.220281
日期:2022.9.5
achieved with high chemoselectivity. In addition, several control experiments revealed that a phenolic hydroxygroup was silylated much faster than a primary alcohol in both an inter- and intramolecular manner. The reactivity toward silylation under these systems might stem from the pKa of the hydroxygroup.