METHOD FOR REGIOSELECTIVE SYNTHESIS OF 1-ALKYL-3-HALOGENALKYLPYRAZOLE-4-CARBOXYLIC ACID DERIVATIVES Russian patent published in 2018 - IPC C07D231/14 C07D231/12 C07C251/76 C07C251/86 

FIELD: chemistry.

SUBSTANCE: invention concerns a process for the regioselective synthesis of 1-alkyl-3-haloalkylpyrazole-4-carboxylic acid derivatives of formula (I) below, in which R¹ means alkyl of 1 to 12 carbon atoms, R² means a residue selected from alkyl radicals having 1 to 4 carbon atoms which are substituted by one, two or three halogen atoms selected from fluorine, chlorine and bromine, Y denotes (C=O)OR³, where R³ means alkyl of 1-12 carbon atoms. Essence of the proposed method is that the hydrazone of acrylic acid of formula (VI), in which R¹ and Y are as defined above, and R⁸ and R⁹ independently of each other, respectively, are alkyl of 1 to 12 carbon atoms, are reacted with α,αdihalogenamine of formula (XI), in which R² is as defined above, and X is fluorine, chlorine and bromine or iodine, and R¹⁰ and R¹¹ independently of each other, respectively, are alkyl of 1 to 12 carbon atoms, followed by cyclization of the resulting the compounds of formula (VII), in which the radicals R¹, R², R⁸, R⁹ and Y is as defined above, and Z is NR¹⁰R¹¹. Invention also relates to a salt of an intermediate of formula (VII).

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EFFECT: present invention relates to a process for the regioselective synthesis of 1-alkyl-3haloalkyl-pyrazole-4-carboxylic acid derivatives by reacting derivatized hydrazines with 2-fluoroacyl-3-amino-acrylic acid derivatives, and subsequent cyclization, as well as in the method intermediates resulting hydrazones.

4 cl, 5 ex