It is known that 5-dinitromethyl-2-methyl-2H-tetrazole (I) reacts with diazomethane to give isomeric methyl (2-methyltetrazol-5-yl)nitromethanenitronates and (1,3-dimethyl-1H-tetrazol-5-yl)dinitromethylide [1]. With a view to study how the nature of substituted 5-dinitromethyltetrazoles affects the direction of their reactions with diazo compounds, we have synthesized an analog of tetrazole (I), 5-(chlorodinitromethyl)-2- methyl-2H-tetrazole (II), and examined its reactions with diazomethane (III) and diazoethane (IV). Tetrazole (II) was prepared in 70% yield by chlorination of azole I potassium salt.