- Discovery and structure-activity relationships of urea derivatives as potent and novel CCR3 antagonists
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The synthesis and structure-activity relationships of ureas as CCR3 antagonists are described. Optimization starting with lead compound 2 (IC 50 = 190 nM) derived from initial screening hit compound 1 (IC 50 = 600 nM) led to the iden
- Nitta, Aiko,Iura, Yosuke,Tomioka, Hiroki,Sato, Ippei,Morihira, Koichiro,Kubota, Hirokazu,Morokata, Tatsuaki,Takeuchi, Makoto,Ohta, Mitsuaki,Tsukamoto, Shin-Ichi,Imaoka, Takayuki,Takahashi, Toshiya
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scheme or table
p. 4951 - 4954
(2012/08/28)
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- Parallel synthesis of a library of benzoxazoles and benzothiazoles using ligand-accelerated copper-catalyzed cyclizations of ortho-halobenzanilides
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A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C-O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination pathway through a Cu(I)/Cu(III) manifold. The reaction is also applicable to the formation of benzothiazoles. A variety of ligands including 1,10-phenanthroline and N,N′- dimethylethylenediamine were shown to provide ligand acceleration/stabilization in the reaction. Optimal conditions for cyclization used a catalyst combination of CuI and 1,10-phenanthroline (10 mol %). The method was amenable to a parallel-synthesis approach, as demonstrated by the synthesis of a library of benzoxazoles and benzothiazoles substituted at various positions in the ring. Most examples utilized the cyclization of ortho-bromoanilides, but orthoiodoanilides and ortho-chloroanilides also undergo a reaction under these conditions. The rate of reaction of the ortho-haloanilides follows the order I > Br > Cl, consistent with oxidative addition being the rate-determining step.
- Evindar, Ghotas,Batey, Robert A.
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p. 1802 - 1808
(2007/10/03)
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