Imidic acid derivatives are potential precursors of heterocyclic compounds which contain at least one nitrogen atom. The results of our research on the application of N-vinylimidoyl, N-arylimidoyl and hydrazonyl derivatives in the synthesis of pyridines, pyrimidines, isoquinolines, quinazolines, 1,2,4-triazoles, tetrazines and others are presented.