For methyl isocyanate, two versions of the phosgenation process and two nonphosgenation processes via ethylene carbonate and n-methylformamide are reviewed. Each is a selective preemergent type. Patents covering their composition and use will expire within a few years. The technology and cost of making the major intermediates for these herbicides are also evaluated because production of these intermediates is small and they contribute heavily to the cost of herbicide production. Chloroacetic acid is used to make the intermediate for glyphosate.
Chloroacetic acid has many uses in syntheses.
This report, therefore, serves a broader purpose than simply covering the three subject herbicides. The process economic data in this report are also useful for examining the degree of intermediate integration necessary to compete in the production of these herbicides. Since few pesticide producers are fully integrated into intermediate production, there may be a market opportunity here. All rights reserved .