Isouron would have been manufactured using the same industrial chemistry applied to other N,N disubstituted phenylurea herbicides. Its structure indicates a two stage production process: first, synthesis of the tert butyl substituted isoxazole intermediate, typically via cyclisation of appropriate beta keto precursors; second, reaction of this heterocycle with dimethylurea or a dimethylcarbamoyl chloride/isocyanate equivalent under anhydrous, base scavenged conditions. Carbamoylation is exothermic, so manufacturers used controlled temperature, inert gas blanketed reactors similar to those used for diuron and linuron. After coupling, the crude product underwent neutralisation, filtration, solvent exchange, and drying to yield technical grade isouron.
