In this paper, results of the research on the application of thin layer chromatography (TLC) for the determination of 1,1diamino-2,2-dinitroethene (FOX-7, DADNE) and its precursors produced in the synthetic path starting from 2-methylpyrimidine-4,6(1H,5H)-dione are presented. Analytical parameters of the substances and methodology of their quantitative analysis were determined, and the results obtained were used for monitoring the FOX-7 synthesis process.