Process Development for the Synthesis of BI 1702135: A Concise Design Enabled by Selective Acylation of a 2-Aminobenzimidazole Intermediate

The route design and process development for the synthesis of BI 1702135 are described. The synthetic design centers around an amide synthesis involving a 2-amino benzimidazole analog 4 that has two competing acylation sites. A highly selective acylation protocol at the desired N-2′ site was identified. Robust and convenient processes were developed for each step in this five-step synthesis of BI 1702135.