Heterocyclic compounds could be any cyclic organic compound with at least one atom being an element other than carbon. This is a simple explanation because some heterocyclic compounds have properties similar to other aliphatic compounds and can therefore not be classified as heterocycles (Schmid 1996). The importance of heterocycle is apparent in the wealth and variety of such compounds that occur naturally or are prepared on commercial scale by drugs and dye companies. Many heterocycles fulfill important physiological functions in plants and animal.