A herbicide for post-emergence weed control. It has a low aqueous solubility and a low volatility. There is a low potential for leaching to groundwater based on its chemical properties. It is not expected to be persistent in soil or water systems. It is moderately toxic via the oral route to mammals, is an endocrine disrupting chemical and a skin sensitiser. It is highly toxic to fish but less so to other aquatic and terrestrial biodiversity.
Commercial production of bromoxynil butanoate builds directly on the established industrial synthesis of bromoxynil, which is made by brominating 4 hydroxybenzonitrile through controlled electrophilic aromatic substitution. Once the parent phenolic herbicide is obtained, manufacturers convert it into the butanoate ester by acylating the phenolic hydroxyl group with butanoyl chloride or a comparable butanoic anhydride, using a base to neutralise the liberated hydrogen chloride and drive the reaction to completion. The resulting ester is purified to remove unreacted acid chloride and residual bromoxynil, yielding technical grade bromoxynil butanoate suitable for formulation.
