CoCl2 + 7NaNO2 + 2CH3COOH → Na3[Co(NO2)6] + 2NaCl + 2CH3COONa + NO + H2O
Cobalt(II) chloride react with sodium nitrite and acetate acid to produce sodium hexanitrocobaltate(III), sodium chloride, sodium acetate, nitric oxide and water. This reaction takes place at a temperature 50-60°C.