In the vast landscape of pharmaceutical science, medicinal chemistry serves as the cornerstone, bridging the gap between the realms of chemistry and biology. It is the art and science of designing, synthesizing, and developing pharmaceutical agents molecules that alleviate human suffering, enhance well-being, and combat diseases. This book, Medicinal Chemistry, embarks on a comprehensive exploration of this fascinating discipline. Within these pages, readers will embark on a journey that delves into the intricacies of drug discovery and development. The preface serves as an invitation to all those curious minds who wish to grasp the fundamental concepts underlying the synthesis, structure-activity relationships, and mechanisms of action of bioactive molecules. The journey begins with a historical overview, tracing the evolution of medicinal chemistry from ancient herbal remedies to the cutting-edge techniques of modern drug design. Understanding the historical context is essential for appreciating the strides made in contemporary medicinal chemistry. A solid foundation in organic and inorganic chemistry is vital. This book provides a clear elucidation of the chemical principles and reactions that underpin the synthesis of medicinal agents. It covers topics ranging from molecular structures and bonding to stereochemistry and reaction mechanisms, empowering readers with the essential toolkit for drug design. Medicine meets biology in this section, where readers will explore the intricacies of biological macromolecules, enzyme kinetics, and cell signalling pathways. An understanding of how drugs interact with biological targets is pivotal for rational drug design. Guided by the principles of structure-based drug design, readers will learn the art of crafting molecules with specific biological activities.