Selective Endothelin A Receptor Antagonists. 4. Discovery and Structure−Activity Relationships of Stilbene Acid and Alcohol Derivatives
作者:Peter C. Astles、Thomas J. Brown、Frank Halley、Caroline M. Handscombe、Neil V. Harris、Clive McCarthy、Iain M. McLay、Peter Lockey、Tahir Majid、Barry Porter、Alan G. Roach、Christopher Smith、Roger Walsh
DOI:10.1021/jm970847e
日期:1998.7.1
This publication describes the synthesis and optimization of a novel series of stilbene endothelin antagonists. Analysis of the SAR established for previous papers in this series prompted the design and synthesis of (Z)-4-phenyl-5-(3-benzyloxyphenyl)pent-4-enoic acid 3 which was found to be a moderately active inhibitor of the binding of [I-125]ET-1 to ETA receptors with an IC50 Of 6 mu M. More interestingly, the intermediate compound (E)-2-phenyl-3-(3-enzyloxyphenyl)-propenoic acid 5 was equiactive with 3. Optimization of 5 resulted in the preparation of (E)2-phenyl-3-(2-cyano-5-(thien-3-ylmethoxy))phenylpropenoic acid 18 (RPR111723) which had an IC50 in the binding assay of 80 nM on the ETA receptor and a pK(B) of 6.5 in the functional assay, measured on rat aortic strips. Reduction of the acid group of 5 gave the first nonacidic ETA antagonist in our series, (E)-2-phenyl-3-(3-benzyloxyphenoxy)prop2-enol 6 with an IC50 Of 20 mu M. Optimization of 6 resulted in the preparation of 2-(2-methylphenyl)-3-(2-cyano-5-(thien-3-ylmethyl)phenyl)prop-2-enol 33 with an IC50 Of 300 nM on the ETA receptor.