4-Fluororesorcinol (CAS number 103068-41-3) is a fluorinated resorcinol, a meta-substituted benzenediol. One of the key applications of 4-fluororesorcinol is to synthesize fluorinated fluoresceins. One synthetic route is 4-fluororesorcinol reacting with benzaldehyde derivatives and followed by an oxidation by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Another method includes a reaction of 4-fluororesorcinol with phthalic anhydride catalyzed by zinc chloride or methanesulfonic acid. It is feasible to synthesize bent-core azo-benzene liquid crystal mesogens from 4-fluororesorcinol with a bending angle of 121.5°.
4-Fluororesorcinol can also chelate to the copper center in oxy-tyrosinase causing inactivation of the tyrosinase.