反应详情

Key building block (E)-2-{4-[2-(2-tert-butoxycarbonylamino-phenylcarbamoyl)-vinyl]-phenyl}-4-(tert-butyl-dimethyl-silanyloxy)-butyric acid ethyl ester (II) can be prepared according to Scheme 6. Starting with commercially available 2-bromo-ethanol (XXIX), silylation with tert-butyldimethylsilyl chloride provides (2-bromo-ethoxy)-tert-butyl-dimethyl-silane (XXX). Alkylation of the potassium enolate of (4-bromo-phenyl)-acetic acid ethyl ester with XXX furnishes 2-(4-bromo-phenyl)-4-(tert-butyl-dimethyl-silanyloxy)-butyric acid ethyl ester (XXXI). Heck reaction of XXXI with (2-acryloylamino-phenyl)-carbamic acid tert-butyl ester gives key building block 2-{4-[2-(2-tert-butoxycarbonylamino-phenylcarbamoyl)-vinyl]-phenyl}-4-hydroxy-butyric acid ethyl ester (II).