Heterocyclic chemistry is a branch of chemistry that focuses on the study of heterocycles, which are ring-shaped compounds containing at least one atom that is not carbon. These non-carbon atoms can include elements like nitrogen, oxygen, or sulfur. Heterocycles are important because they are found in many natural products, pharmaceuticals, and agrochemicals, making them essential for various applications in medicine and agriculture. One well-known example of a heterocyclic compound is pyridine, which contains a nitrogen atom in its six-membered ring. Heterocyclic compounds can exhibit unique chemical properties and biological activities, leading to their use in drugs like antibiotics and antidepressants. Understanding heterocyclic chemistry helps scientists design new compounds with specific functions.