METHOD OF PRODUCING PHENMEDIPHAM Russian patent published in 2024 - IPC C07C269/02 C07C269/06 C07C271/58 

FIELD: chemistry.

SUBSTANCE: invention relates to production of pesticides, more specifically to a method of producing phenmedipham, which is a systemic postemergence herbicide for protecting crops of sugar, fodder and table beet. Method involves initial reaction of methanol with triphosgene in the presence of a base in an organic solvent medium in an inert gas atmosphere or in air without moisture access to obtain methyl chloroformate in the organic solvent medium. Further, the obtained solution is used in reaction with 3-aminophenol in the presence of a base in the medium of an organic solvent or in a mixture thereof with water, which leads to production of methyl-N-(3-hydroxyphenyl)carbamate in an organic solvent medium. Obtained solution is used in a reaction with m-tolyl isocyanate to obtain the desired product, followed by extraction and purification.

EFFECT: improved performance of the phenmedipham production process by eliminating the use of intermediate methyl chloroformate and methyl-N-(3-hydroxyphenyl)carbamate in individual form, id est without their extraction and purification during the process, simplification of its organization and improvement of safety with obtaining of target product of high quality with output of 80–85 %.

4 cl, 5 ex