Abstract:
The contents of this thesis have been divided into five chapters based on the results of experimental works performed during the complete course of the research period. The introductory chapter of the thesis presents an overview of different aspects of heterocyclic chemistry with special reference to five and six membered heterocycles and their synthesis using tribromides and copper catalysts. Chapters 2 and 3 describe the syntheses of 1, 4- dithiins and 2-iminothiazolines using a ditribromide reagent (EDPBT). Chapters 4 and 5 illustrate copper-catalyzed syntheses of substituted 2-mercapto benzimidazoles and 2- substituted benzothiazoles via inter and intramolecular hetero-arylations. Each chapter constitute four sections, describing introduction, present work, experimental work and spectral data respectively.CHAPTER I. Introduction to Heterocyclic Chemistry This chapter highlights the nomenclature, definition and importance of heterocycles and literature background for the synthesis of heterocycles using organic ammonium tribromides (OATBs) and copper catalysts. Heterocycles make up an exceedingly important class of compounds. More than half of all known organic compounds are heterocycles. Almost all the compounds we know as drugs, most vitamins and many other natural products are heterocycles. The class also includes many other compounds of biological importance, such as nucleic acids, carbohydrates, hormones, and pigments. Heterocyclic compounds are key components of pharmaceutical chemistry and therefore, they have been a fruitful source of inspiration for the design of structural analogues to be used as pharmacological tools as well as new drugs. One of the reasons for the wide spread use of heterocyclic compounds as shown below, is that their structures can be subtly manipulated to achieve a required modification in function..
