METHOD OF PRODUCING PYRAZOLES Russian patent published in 2012 - IPC C07D231/14 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid of formula I , which involves a) reaction of a compound of formula II , wherein R₁ and R₂ both independently denote C₁-C₆-alkyl, with methylhydrazine in the presence of water and a water-immiscible organic solvent which is inert in saponification reactions, to obtain a compound of formula III, wherein R₁ is as described in formula I; and b) saponification of said compound in situ, which leads to formation of a compound of formula I through b1) adding a base to form an anion of the compound of formula I and subsequent addition of acid to form a compound of formula I; or b2) adding acid to form a compound of formula I. The invention also relates to a method of producing a compound of formula (III).

EFFECT: novel method which enables to obtain an end compound with high output and good quality.

22 cl, 4 ex