ChEBI: Haloxydine is a hydroxyyridine that is 4-hydroxypyridine which is substituted by fluorines at positions 2 and 6, and by chlorines at positions 3 and 5. An obsolete herbicide, formerly used to control selective broad-leaved and grass weeds in crops such as potatoes. It has a role as an EC 2.5.1.117 (homogentisate solanesyltransferase) inhibitor, a herbicide and an agrochemical. It is a hydroxypyridine, an organochlorine compound and an organofluorine compound.
Haloxydine is synthesised through a multi-step process that begins with the construction of the pyridazinone ring via condensation of a hydrazine derivative with a diketone or ketoester. This intermediate is then functionalised by introducing halogen atoms, typically chlorine or fluorine, through electrophilic substitution to enhance herbicidal activity. Subsequent steps involve etherification or acylation to attach alkyl or aryl side chains that improve selectivity and environmental stability. The final compound is purified using recrystallisation or chromatography and formulated for agricultural use. Each step requires careful control of temperature, solvent choice, and reagent stoichiometry to ensure high yield and purity.
Selective. Thought to interfere with carotenoid processes allowing photo-oxidation of chlorophyll to occur. HST inhibitor
