Heterocyclic compounds are important natural products and have widespread uses as pharmaceuticals, dyestuffs, agrochemicals, and pigments. This textbook provides a survey of the various types of heterocyclic ring system. The text has been organized in such a way that the general aspects of the chemistry and properties of heterocyclic compounds are described in the first half of the book and specific classes of heterocycles are then discussed in the second half. Both aromatic and nonaromatic ring systems are included. various methods available for synthesising heterocyclic compounds. This chapter has been expanded and brought up to date in the Second Edition. The second half of the book has been re-organized so that the most common aromatic heterocyclic ring systems are introduced first. Modern applications of heterocyclic chemistry in medicine and in organic synthesis are given prominence in this part of the text. The final chapter provides a guide to the current methods of naming heterocyclic compounds. text, and by a set of problems. Throughout the text numerous references are given to socialist reviews and, where appropriate, to papers from the primary literature. chemistry and for students of biochemistry, pharmacology and related subjects who have a good background knowledge of organic chemistry. It should also be useful as a reference source to more advanced workers in these subjects.