METHOD OF PREPARING 3-HALOGENALKYL-1H- PYRAZOLES Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing 3-halogenealkyl-1H-pyrazole derivative of formula II: wherein R¹ is selected from group consisting of trifluoromethyl, difluoromethyl, pentafluoroethyl and heptafluoropropyl; R³ is phenyl optionally substituted in substituted position by one or more substituents selected from fluorine, chlorine, bromine, methyl, ethyl, methoxy, ethoxy and methylthio. Method comprises treating acetophenol of formula 5: wherein R³ is as defined above, with base and ester of formula 2: wherein R¹ is as defined and R⁵ is lower alkyl and treating the resulting product with-4(aminosulfonyl) phenylhydrazine or salt thereof. EFFECT: effective synthesis of 3-halogenalkyl-1H-pyrazoles which is suitable in large-scale process carried out in single apparatus. 8 cl, 2 ex