反应详情

In analogy to the procedure described in example 1 d], [rac]-2-ethoxy-3-(3-fluoro-4-hydroxy-phenyl)-propionic acid ethyl ester (example 7 a]) was reacted with 2-(2-benzo[1,3]dioxol-5-yl-5-methyl-thiazol-4-yl)-ethanol (prepared from [rac]-4-bromo-3-oxo-pentanoic acid methyl ester [PCT Int. Appl. (2001), WO 01/792023 and benzo[1,3]dioxole-5-carbothioic acid amide in analogy to the procedures described in examples 12 a] and 12 b]) in tetrahydrofuran in the presence of triphenylphosphine and DEAD (diethyl azodicarboxylate) to yield [rac]-3-{4-[2-(2-benzo[1,3]dioxol-5-yl-5-methyl-thiazol-4-yl)-ethoxy]-3-fluoro-phenyl)-2-ethoxy-propionic acid ethyl ester, which was further saponified in analogy to the procedure described in example 4 e], to yield [rac]-3-{4-[2-(2-benzo[1,3]dioxol-5-yl-5-methyl-thiazol-4-yl)-ethoxy]-3-fluoro-phenyl}-2-ethoxy-propionic acid as colorless solid.

1. customdescribed in example 1 d