2,4-Dihydroxyacetophenone (I) is formed by the Friedel-Crafts acetylation of resorcinol. This compound is condensed with diethyl oxalate in sodium ethoxide solution, affording (II). Disodium cromproxate (IV) is conveniently prepared from (II) by treatment with epichlorohydrine in aqueous ethanolic alkaline solution. It is recrystallized from hot water.