Regiospecific synthesis of 1,5-disubstituted-1H-pyrazoles containing differentiated 3,4-dicarboxylic acid esters via Suzuki coupling of the corresponding 5-trifluoromethane sulfonates
作者:Peter S. Dragovich、Thomas M. Bertolini、Benjamin K. Ayida、Lian-Sheng Li、Douglas E. Murphy、Frank Ruebsam、Zhongxiang Sun、Yuefen Zhou
DOI:10.1016/j.tet.2006.11.053
日期:2007.1
A general procedure is described for the regiospecific preparation of 1-substituted-5-hydroxy-1H-pyrazoles containing differentiated ester moieties at the 3- and 4-positions. This process involves the coupling of monosubstituted benzyl carbazates with various malonyl chlorides or acids, deprotection of the coupling products via catalytic hydrogenation, and subsequent derivatization of the resulting