Month 2016 Reaction of Amidrazones with Diaminomaleonitrile: Synthesis of 4- Amino-5-Iminopyrazoles Ashraf A. Aly, a * Alaa A. Hassan, a Stefan Bräse, b Mohsen A.-M. Gomaa, a and Fatmaa M. Nemr a a Department of Chemistry, Faculty of Science, Minia University, 61519 - El-Minia, Egypt b Institute of Organic Chemistry, Karlsruhe Institute of Technology, 76141- Karlsruhe, Germany * E-mail: ashrafaly63@yahoo.com Received October 7, 2015 DOI 10.1002/jhet.2607 Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com). Diaminomaleonitrile and N-arylbenzamidrazones reacted together to give 4-amino-5-iminopyrazoles. A probable reaction mechanism involves firstly removal of ammonia, followed by addition and cylization of the hydrazino-N 2 of amidrazone to the nitrile group in diaminomaleonitrile. The structure of the obtained products was proved by IR, mass, NMR spectra and elemental analyses. J. Heterocyclic Chem., 00, 00 (2016). INTRODUCTION The importance of diaminomaleonitrile (DAMN, hydro- gen cyanide tetramer) as a readily available and cheap building block for the synthesis of various nitrogen hetero- cycles [1,2] has attracted the attention of organic chemists worldwide. For example, DAMN has been used as a pre- cursor for the synthesis of purines [3], pyrimidines [4], pyrazines [5], imidazoles [6], and many more. Moreover, the reactions of DAMN over the last decade including novel methods utilized, new compounds prepared, and sig- nificant applications. Synthesis of Schiff bases and its com- plexes derived from DAMN have gained recent interests as they have different applications in various areas, for exam- ple, as ligand for metal complexes. [7] They were found applicable as dye materials in color chromatography, in fluorescent light emitting devices [8], in pharmacological studies [9], and in the chemical libraries for DNA-binding compounds [10], and so on. Amidrazones represent a class of substances with inter- esting biological properties. It has been established that they can exhibit antibacterial and antifungal [11–13], anti- tumor [14], or antituberculosis activities [15]. They were also found as effective herbicides [16], pesticides [17], and insecticides [18]. The interest in amidrazones and their derivatives stems not only from their biological relevance but also from their applications as precursors and interme- diates for the synthesis of many heterocyclic compounds [19–21] or as ligands in coordination chemistry. Amidrazones can also react with a wide range of transition metals in their neutral or ionic forms, and they show a di- versity of coordination modes [22,23], which can lead to complexes having different geometries and various molec- ular arrangements. Pyrazoles have been the recent target of numerous meth- odologies mostly because of their prevalence as scaffolds in drug discovery programs [24]. They have been used also as bifunctional ligands for metal catalysis [25], as model systems to study excited-state intramolecular proton trans- fers [26], as artificial receptors [27], and as the backbone to numerous scorpionate ligands [28]. One of the important application of aminopyrazoles is that some of them have been used as dyes such as the keratin pyrazole dying com- pounds 1 [1,2] (Fig. 1). Synthetic approach of pyrazoles provides the synthetic chemist with a multitude of choices to construct substituted pyrazoles; almost all of them suffer from either regiochemical infidelity or multi-step sequences. Aly et al. have recently reported the synthesis of pyrazoles from the reaction of amidrazones with ethyl 2-cyano-3,3-bis(methylthio)acrylate [29]. Herein, we investigate the reaction between amidrazones and DAMN. In DAMN, the amino group is considered as a good nucleophile center, therefore, we investigate the compet- itive in nucleophilicity between the two substrates in the course of reaction selectivity. RESULTS AND DISCUSSION The reaction of equal molar of amidrazones 2a–e with DAMN (3) in dry dimethylformamide (DMF) under reflux condition gave, after chromatographic purification and re- crystallization, compounds 4a–e (10–16%, Method I, Scheme 1). The poor yield prompted us to search another © 2016 Wiley Periodicals, Inc.