1. Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
2. Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach an der Riss, Germany
3. Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
4. Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States