The tutorial outlines the chemistry of heterocyclic compounds with three or more heteroatoms. The basic methods of obtaining oxadiazoles, thiadiazoles, triazoles, tetrazoles, oxadiazines, thiadiazines, triazines, tetrazines, their chemical transformations, as well as application in various fields are presented. The educational material is systematized by classes of heterocyclic compounds. Laboratory procedures are provided for the preparation of certain heterocyclic compounds using available reagents.