1. Organic Pharmaceutical Chemistry, Uppsala University, Uppsala Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden, Department of Structural Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden, Department of Lead Generation, Preclinical R&D, and Pharmaceutical and Analytical R&D, AstraZeneca R&D Södertälje, SE-151 85 Södertälje, Sweden, and ACADIA Pharmaceuticals, 3911 Sorrento Valley Boulevard, San Diego, California 92121