Diazodinitrophenol

Diazodinitrophenol (DDNP) was the first diazo compound produced; it was subsequently used to make dyes and explosives. It forms yellow crystals in pure form; however, the color of impure forms may vary from dark yellow to green to dark brown. It is soluble in acetic acid, acetone, concentrated hydrochloric acid, most non-polar solvents and is slightly soluble in water.