Synthesis, instrumental and explosive properties 1,1-diamino-2,2-dinitroethene (FOX-7)

In this work, FOX-7 (C2H4N4O4) has been successfully prepared in the laboratory scale through three main steps. Firstly by the preparation of the precursor 2-methylpyrimidine-4,6-diol (C5H6N2O2) which is also used in pharmaceutical applications in an economic method; the preparation was carried out by the preparation of sodium methoxide (CH3ONa), the condensation reaction of acetamidine hydrochloride (C2H7N2Cl) and diethyl malonate (C7H12O4), filtration process, and finally acidifying step by concentrated hydrochloric acid. Secondly by nitration of the prepared 2-methylpyrimidine-4,6-diol (C5H6N2O2) with a mixed acid (HNO3 / H2SO4). Finally by the hydrolysis step of the intermediate product 2-dinitromethylene-5,5-dinitropyrimidine-4,6-dione (C5H2N6O10) in distilled water. Instrumental characterization as Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscope (SEM) and elemental analysis were carried out to characterize the prepared 2-methylpyrimidine-4,6-diol and FOX-7. The results obtained approved the structures of the prepared 2-methylpyrimidine-4,6-diol and FOX-7. Explosive characterization as sensitivity test (to impact, friction, and heat), detonation velocity and brisance measurements were carried out to characterize the prepared FOX-7. It showed performance properties comparable to RDX, but it has lower sensitivity to impact and heat than RDX. Sensitivity to friction results showed no indication of initiation according to friction was noticed even when applying the maximum force (360 N) of the test apparatus. The performance results obtained showed detonation velocity and brisance more than RDX by 1.3 % and 0.3 % respectively.