Synthesis, Chemistry and Utilities of Diaminoazoles with Special Reference to 3,5-diaminopyrazoles

Background: Although the chemistry of heteroaromatic monoamino azoles has been surveyed more than once in the last decade, the chemistry of the di- and triaminoazoles has not been reviewed. In this article we will survey the synthesis, chemistry and utility of the diaminoazoles. In this review, the chemistry of the diaminoazoles as well as their most important utilities will be surveyed. Objective: The review focuses on recent progress in diaminoazoles (i.e. diaminopyrazoles, diaminoimidazoles, diaminotriazoles and diaminothiazole) with especial references to diaminopyrazoles. The synthesis as well as pharmaceutical utilities are reported. There are several methods for synthesis of diaminopyrazoles. 3,5- Diaminopyrazole and its derivatives are prepared through the reaction of malononitrile or arylhydrazononitrile with hydrazine derivatives. 3,4-Diaminopyrazoles are prepared via nitration of 3-aminopyrazole with subsequent reduction of the produced compound. The diaminopyrazoles have several applications in cosmetic and pharmaceutical industries. They also have useful utilities as a constituent in oxidative hair dyes. Conclusion: We managed to report the common methods for the synthesis of diaminoazoles with especial reference to aminopyrazoles that are prepared through the reaction of malononitrile or hydrazononitriles with hydrazine derivatives. Some important applications that include pharmaceutical utilities such as hair dye constituents are reported.