1,5-Dihydroxynaphthalene

1,5-Dihydroxynaphthalene is an organic compound with the formula C$10$H$6$(OH)$2$. It is one of several isomers of dihydroxynaphthalene. A white solid, degraded samples often appear grey to light brown solid that are soluble in polar organic solvents. It is a precursor to certain dyes.

Preparation and use
1,5-Dihydroxynaphthalene is prepared from naphthalene-1,5-disulfonic acid by hydrolysis with strong base followed by acidification.

It couples with various aryl diazonium salts to give diazo dyes. Oxidation with chromium trioxide gives juglone, a naturally occurring dye.

In supramolecular chemistry, 1,5-dihydroxynaphthalene is a popular reagent.