The chapters in this book are written to accentuate the interdependency and synergy between drug discovery and process development disciplines to advance a new chemical entity into clinical trials and eventually to the market. Due to the success of our previous books (Comprehensive Accounts of Pharmaceutical Research and Development: From Discovery to Late-Stage Process Development, Volumes 1 and 2), the editors sought to further arm experienced modern synthetic organic chemists, and budding researchers perhaps still in universities with real world examples from the pharmaceutical industry. In addition, the chapters contain citations of a large number of valuable selected references to the primary literature. The book highlights the tireless efforts of Discovery and Process Chemists, and their roles in the advancement of drug discovery and development. The editors were motivated to create this book by our appreciation of the value of chemical research by both Discovery and Process Chemists in producing new pharmaceutical entities. Their combined efforts make it possible to introduce novel and effective drugs into the market to treat hundreds of millions of patients and alleviate their suffering, improve their quality of life and possibly save their lives from diseases and disorders. The chapters presented in this book are written by a selected group of outstanding, highly accomplished Medicinal and Process Chemists with noted experiences and diverse backgrounds representing some of the top pharmaceutical companies. The chapters highlight examples of emerging concepts, new developments and challenges arising in the discovery of new drug candidates and the development of new practical synthetic chemistry processes to produce these drug candidates on large scale. The story leading up to the discovery of each drug or drug candidate is presented by the Discovery Chemist(s), and then the Process Chemist(s) describe the development of the same drug to give the reader a complete story of drug discovery and development. The reader will experience a rare and unique opportunity to obtain the complete perspectives of Discovery and Process Chemistry in a single book. While most of these topics have appeared in the primary literature where space is critical and brevity valued, the book permits the editors and contributors to tell the complete tales as stories, from start to finish or to the current state of the drug development.