4-Chlorobenzaldehyde → [Rac]-3-(7-{2-[2-(4-chloro-phenyl)-5-methyl-oxazol-4-yl]-ethoxy}-benzo[b]thiophen-4-yl)-2-ethoxy-propionic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

In analogy to the procedure described in example 17 a], [rac]-2-ethoxy-3-(7-hydroxy-benzo[b]thiophen-4-yl)-propionic acid methyl ester (example 151 a]) was reacted with 2-[2-(4-chloro-phenyl)-5-methyl-oxazol-4-yl]-ethanol (prepared by conversion of the 4-chloro-benzaldehyde into 2-[2-(4-chloro-phenyl)-5-methyl-oxazol-4-yl]-ethanol in analogy to the sequence described in examples 21 a] to 21 e]) in the presence of triphenylphosphine and DEAD (diethyl azodicarboxylate) to yield [rac]-3-(7-{2-[2-(4-chloro-phenyl)-5-methyl-oxazol-4-yl]-ethoxy}-benzo[b]thiophen-4-yl)-2-ethoxy-propionic acid methyl ester, which was further saponified in analogy to the procedure described in example 91 e] to yield [rac]-3-(7-{2-[2-(4-chloro-phenyl)-5-methyl-oxazol-4-yl]-ethoxy}-benzo[b]thiophen-4-yl)-2-ethoxy-propionic acid as colorless oil.

Herkunft & Nachweise