US Patent 7452994 Synthesis of enantiomerically pure amino-substituted fused bicyclic rings

This invention describes various processes for synthesis and resolution of racemic amino-substituted fused bicyclic ring systems. One process utilizes selective hydrogenation of an amino-substituted fused bicyclic aromatic ring system. An alternative process prepares the racemic amino-substituted fused bicyclic ring system via nitrosation. In addition, the present invention describes the enzymatic resolution of a racemic mixture to produce the (R)- and (S)-forms of amino-substituted fused bicyclic rings as well as a racemization process to recycle the unpreferred enantioner. Further provided by this invention is an asymmetric synthesis of the (R)- or (S)-enantiomer of primary amino-substituted fused bicyclic ring systems.