Synthetic approaches to 1-(2-chlorophenyl)isoquinoline-3-carboxylic acid

Abstract

In connection with our research of new antitumor compounds, previously undescribed approaches to the 1-(2-chlorophenyl)isoquinoline-3-carboxylic acid 9 are reported here. Two related accesses from phenylethylamine or amphetamine were investigated and were found to be successful. A more robust synthesis, using Suzuki's cross-coupling between 2-chlorophenylboronic acid 15 and the previously unreported methyl-1-bromoisoquinoline-3-carboxylate 14 was also developed. This synthetic route provides the ground for a combinatorial approach to the core structure of new potential peripheral benzodiazepine receptor ligands.