Heterocyclic chemistry is an important branch of Organic Chemistry since there are innumerable heterocyclic systems available naturally, and many more are being synthesized by humans in labs on a regular basis. Many biological materials required for life are heterocycles. Nucleic acids, for example, are long chains of heterocyclic units linked together. Most of the naturally occurring colors, vitamins, and antibiotics are heterocyclic compounds. Synthetic heterocycles are used in modern civilization as medicines, insecticides, and polymers.The best MCR is versatile enough to produce intermediates with a variety of functional groups, which may further react to generate a varied range of products. The rising interest in combinatorial synthesis and the pharmaceutical industry has prompted further research into MCRs resulting in several advancements in the design and its application for the creation of varied heterocycles of biological interest.