1,1-Diamino-2,2-dinitroethene (FOX-7) was synthesized by condensation of diethyl malonate with acetamidine hydrochloride at 50'C in MeOH in presence of Na and following nitration of the 2-methyl-4,6-pyrimidinedione intermediate in concd. H 2 SO 4 at 15-20 degrees C. The FOX-7 produced was tested for surface development, grain size distribution, apparent d., sensitivity to impact and detonation rate. The best quality of FOX-7 was achieved when aq. Me 2SO was used as the solvent for crystn. The product can be used as an additive to plastic bonded explosives to reduce their sensitivity to mech. stress.