An efficient new route to dihydropyranobenzimidazole inhibitors of HCV replication.

A class of dihydropyranobenzimidazole inhibitors was recently discovered that acts against the hepatitis C virus (HCV) in a new way, binding to the IRES-IIa subdomain of the highly conserved 5' untranslated region of the viral RNA and thus preventing the ribosome from initiating translation. However, the reported synthesis of these compounds is lengthy and low-yielding, the intermediates are troublesome to purify, and the route is poorly structured for the creation of libraries. We report a streamlined route to this class of inhibitors in which yields are far higher and most intermediates are crystalline. In addition, a key variable side chain is introduced late in the synthesis, allowing analogs to be easily synthesized for optimization of antiviral activity

Chem 432

Chem 43

An efficient new route to dihydropyranobenzimidazole inhibitors of HCV replication.

A class of dihydropyranobenzimidazole inhibitors was recently discovered that acts against the hepatitis C virus (HCV) in a new way, binding to the IRES-IIa subdomain of the highly conserved 5' untranslated region of the viral RNA and thus preventing the ribosome from initiating translation. However, the reported synthesis of these compounds is lengthy and low-yielding, the intermediates are troublesome to purify, and the route is poorly structured for the creation of libraries. We report a streamlined route to this class of inhibitors in which yields are far higher and most intermediates are crystalline. In addition, a key variable side chain is introduced late in the synthesis, allowing analogs to be easily synthesized for optimization of antiviral activity

New Route to the Ergoline Skeleton via Cyclization of 4‑Unsubstituted Indoles

A new route to the ergoline skeleton has been developed that does not require prior functionalization of the indole 4-position. The indole nucleus is introduced late in the synthesis to allow for eventual efficient introduction of substituents in this region. Key steps include Negishi coupling of a three-carbon chain to a bromonicotinate ester, Fischer indole synthesis to facilitate incorporation of substituents via phenylhydrazines, and Pd-catalyzed cyclization to form the ergoline C ring