📓 In recent years researchers are very much interested in the chemistry of heterocyclic compounds due to the wide range of their industrial applications in the area of organic chemistry. This book contains the synthesis, characterization and biological investigations of heterocyclic compounds: Azetidinone and 4-Thiazolidinone. This book introduces the methods of preparation on quinazoline and Schiff bases. It discusses at length the procedures of preparation of Azetidinone and 4-Thiazolidinone. Antimicrobial activities and NMR and IR spectroscopy of both of them are also discussed. This book will be immensely helpful for researchers and young research scholars to have a good source of reference for their work. Industry practitioners will find the results and discussions of this book very helpful in their routine tasks. Several methods of direct implementation of this work in large scale R & D projects are also discussed.