METHOD OF SYNTHESIS OF ETHYL-ALPHA-2-DICHLORO-5-[4-(DIFLUORO-METHYL)-4,5-DIHYDRO-3- METHYL-5-OXO-1H-1,2,4-TRIAZOLE-1-YL]-4-FLUOROBENZENE PROPIONATE Russian patent published in 2002 - IPC

FIELD: organic chemistry, chemical technology, herbicides. SUBSTANCE: invention describes the improved method of synthesis of the known herbicide ethyl- -α-2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazole-1-yl]-4- fluorobenzene propionate by diazotization of 4-difluoro-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4- chlorophenyl)-1H-1,2,4-triazole and arylation of ethyl acrylate with diazonium salt synthesized. Diazotization and arylation are performed simultaneously and 0.05-0.5 equivalent of copper (I) chloride, hydrochloric acid, ethyl acrylate and sodium nitrite are added to derivative of 1,2,4-triazole in 10-30 equivalents of acetone one after another. EFFECT: improved method of synthesis. 3 cl