Synthesis and properties of hydrazones bearing amide, thioamide and amidine functions

This review provides detailed methods for the synthesis, structures and chemical properties of hydrazones bearing carboxamide, thioamide and amidine functions. The main accent was put on the cyclization reactions leading to pyrazoles, thiazoles, 1,2,3-triazoles, 1,2,3-thiadiazoles, 1,2,4triazines and other heterocyclic compounds. In addition, we have reviewed methods for the synthesis of substrates for pericyclic reactions from the hydrazones.